Rotate android image without resizing it?

I'm "translating" a program written in C # for Android, and I had a problem while performing the rotation of an image. The code works normally, but returns an image of a different size than the original, I understand why the new image has a different size, but how can I make that image come back the same size as the original, leaving out the image's edges? / p>

The rotated image is not displayed to the user, it is only used internally to perform some calculations.

public static Bitmap Rotate(Bitmap source, int anchorX, int anchorY, float angle)
{
    Matrix matrix = new Matrix();
    matrix.postRotate(angle, anchorX, anchorY);
    return = Bitmap.createBitmap(source, 0, 0, source.getWidth(),
            source.getHeight(), matrix, true);
}

Original C # :

public static Bitmap Rotate(Bitmap image, Point offset, float angle)
{
    if (image == null) return null;
    Bitmap rotatedBmp = new Bitmap(image.Width, image.Height);
    rotatedBmp.SetResolution(image.HorizontalResolution,  image.VerticalResolution);
    Graphics g = Graphics.FromImage(rotatedBmp); 
    g.TranslateTransform(offset.X, offset.Y);
    g.RotateTransform(angle);
    g.TranslateTransform(-offset.X, -offset.Y);
    g.DrawImage(image, new PointF(0, 0)); 
    return rotatedBmp;
}