Google Maps Direction API only works the first time

I have the following code that creates a route using the Google Maps API Directions:

public class MapsActivity extends FragmentActivity implements GoogleApiClient.ConnectionCallbacks, GoogleApiClient.OnConnectionFailedListener, OnMapReadyCallback {
    private LatLng position;

    private Polyline polyline;
    private List<LatLng> list;
    private long distance;

    private GoogleMap mMap;
    private GoogleApiClient googleApiClient;

    @Override
    protected void onCreate(Bundle savedInstanceState)  {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_maps);

        // Obtain the SupportMapFragment and get notified when the map is ready to be used.
        SupportMapFragment mapFragment = (SupportMapFragment) getSupportFragmentManager()
                .findFragmentById(R.id.map);
        mapFragment.getMapAsync(this);
    }

    @Override
    public void onMapReady(GoogleMap googleMap) {
        mMap = googleMap;

        pegarLocalização();

        mMap.setOnMapClickListener(new GoogleMap.OnMapClickListener() {
            @Override
            public void onMapClick(LatLng latLng) {
                limparMapa();
                adicionarLocal();
                adicionarDestino(latLng);
                pegarLocalização();
                getRoute(position, latLng);
            }
        });

        mMap.setOnMarkerClickListener(new GoogleMap.OnMarkerClickListener() {
            @Override
            public boolean onMarkerClick(Marker marker) {
                if(marker.getTitle().isEmpty()) {
                    return false;
                } else {
                    return true;
                }
            }
        });
    }

    public void adicionarLocal() {
        mMap.addMarker(new MarkerOptions()
                .position(position)
                .title("Sua Localização"));
        CameraPosition cp = new CameraPosition.Builder().target(position).zoom(15).build();
        CameraUpdate cu = CameraUpdateFactory.newCameraPosition(cp);
        mMap.moveCamera(cu);
    }

    public void adicionarDestino(LatLng position) {
        // Add a marker in Sydney and move the camera
        mMap.addMarker(new MarkerOptions()
                .position(position)
                .title(""));
        CameraPosition cp = new CameraPosition.Builder().target(position).zoom(10).build();
        CameraUpdate cu = CameraUpdateFactory.newCameraPosition(cp);
        mMap.moveCamera(cu);
    }

    public void limparMapa() {
        mMap.clear();
    }

    public void pegarLocalização() {
        ActivityCompat.requestPermissions(MapsActivity.this, new String[]{android.Manifest.permission.ACCESS_COARSE_LOCATION, android.Manifest.permission.ACCESS_FINE_LOCATION}, 0);

        if (ContextCompat.checkSelfPermission(MapsActivity.this, android.Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            if (ActivityCompat.shouldShowRequestPermissionRationale(MapsActivity.this, android.Manifest.permission.ACCESS_COARSE_LOCATION)) {
                Toast.makeText(getBaseContext(), "Você já negou antes essa permissão! \nPara saber a sua localização necessitamos dessa permissão!", Toast.LENGTH_LONG).show();

                ActivityCompat.requestPermissions(MapsActivity.this, new String[]{android.Manifest.permission.ACCESS_COARSE_LOCATION, android.Manifest.permission.ACCESS_FINE_LOCATION}, 0);
            } else {
                ActivityCompat.requestPermissions(MapsActivity.this, new String[]{android.Manifest.permission.ACCESS_COARSE_LOCATION, android.Manifest.permission.ACCESS_FINE_LOCATION}, 0);
            }
        }else {
            googleApiClient = new GoogleApiClient.Builder(this)
                    .addConnectionCallbacks(this)
                    .addOnConnectionFailedListener(this)
                    .addApi(LocationServices.API)
                    .build();

            googleApiClient.connect();
        }
    }

    @Override
    public void onConnected(@Nullable Bundle bundle) {

        if (ContextCompat.checkSelfPermission(MapsActivity.this, android.Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_GRANTED) {

            Location lastLocation = LocationServices.FusedLocationApi.getLastLocation(googleApiClient);

            position = new LatLng(lastLocation.getLatitude(), lastLocation.getLongitude());

            adicionarLocal();
        }
    }

    @Override
    public void onConnectionSuspended(int i) {
    }

    @Override
    public void onConnectionFailed(@NonNull ConnectionResult connectionResult) {
        Toast.makeText(getBaseContext(), "Conexão falhou!", Toast.LENGTH_LONG).show();
    }

    //-------------------------------------------------ROTA-------------------------------------------------

    public void drawRoute(){
        PolylineOptions po;

        if(polyline == null){
            po = new PolylineOptions();

            for(int i = 0; i < list.size(); i++){
                po.add(list.get(i));
            }

            po.color(Color.BLACK).width(4);
            polyline = mMap.addPolyline(po);
        }
        else{
            polyline.setPoints(list);
        }
    }

    // WEB CONNECTION
    public void getRoute(final LatLng origin, final LatLng destination){
        new Thread(){
            public void run(){
                String url= "http://maps.googleapis.com/maps/api/directions/json?" +
                        "origin=" + origin.latitude + "," + origin.longitude +
                        "&destination=" + destination.latitude+","+destination.longitude +
                        "&sensor=false";

                HttpResponse response;
                HttpGet request;
                AndroidHttpClient client = AndroidHttpClient.newInstance("route");

                request = new HttpGet(url);
                try {
                    response = client.execute(request);
                    final String answer = EntityUtils.toString(response.getEntity());

                    runOnUiThread(new Runnable(){
                        public void run(){
                            try {
                                list = buildJSONRoute(answer);
                                drawRoute();
                            }
                            catch(JSONException e) {
                                e.printStackTrace();
                            }
                        }
                    });

                }
                catch(IOException e) {
                    e.printStackTrace();
                }
            }
        }.start();
    }

    // PARSER JSON
    public List<LatLng> buildJSONRoute(String json) throws JSONException{
        JSONObject result = new JSONObject(json);
        JSONArray routes = result.getJSONArray("routes");

        distance = routes.getJSONObject(0).getJSONArray("legs").getJSONObject(0).getJSONObject("distance").getInt("value");

        JSONArray steps = routes.getJSONObject(0).getJSONArray("legs").getJSONObject(0).getJSONArray("steps");
        List<LatLng> lines = new ArrayList<LatLng>();

        for(int i=0; i < steps.length(); i++) {

            String polyline = steps.getJSONObject(i).getJSONObject("polyline").getString("points");
            for(LatLng p : decodePolyline(polyline)) {
                lines.add(p);
            }
        }
        return(lines);
    }

    // DECODE POLYLINE
    private List<LatLng> decodePolyline(String encoded) {

        List<LatLng> listPoints = new ArrayList<LatLng>();
        int index = 0, len = encoded.length();
        int lat = 0, lng = 0;

        while (index < len) {
            int b, shift = 0, result = 0;
            do {
                b = encoded.charAt(index++) - 63;
                result |= (b & 0x1f) << shift;
                shift += 5;
            } while (b >= 0x20);
            int dlat = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
            lat += dlat;

            shift = 0;
            result = 0;
            do {
                b = encoded.charAt(index++) - 63;
                result |= (b & 0x1f) << shift;
                shift += 5;
            } while (b >= 0x20);
            int dlng = ((result & 1) != 0 ? ~(result >> 1) : (result >> 1));
            lng += dlng;

            LatLng p = new LatLng((((double) lat / 1E5)), (((double) lng / 1E5)));
            Log.i("Script", "POL: LAT: "+p.latitude+" | LNG: "+p.longitude);
            listPoints.add(p);
        }
        return listPoints;
    }
}

But it only works the first time, if I close and open the application it works again, then stops working.

Can anyone help?