Android natively has the option to encrypt the phone. It's under Settings, security.

I would use the native Android system. Of course, as a colleague said, you have third-party tools that will do the trick, but it will always be safer to do it with the OS tools themselves.

Mostly because Android encryption prevents the content from being read even at runtime of the system. Any encryption applied at the service level will not be able to cover the device startup itself, or if it does, it will do so after the device has already started (imposing an extra lock screen), which enables specific attacks that could compromise the security of that encryption.