Custom splash screen defined in FlutterActivity

Locate your application’s implementation of provideSplashScreen()
within its FlutterActivity and delete it. This implementation should involve
the construction of your application’s custom splash screen
as a Drawable. For example:

    
@Override
public SplashScreen provideSplashScreen() {
    // ...
    return new DrawableSplashScreen(
        new SomeDrawable(
            ContextCompat.getDrawable(this, R.some_splash_screen)));
}

Use the steps in the section directly following to ensure that your
Drawable splash screen (R.some_splash_screen in the previous example)
is properly configured as your application’s custom launch screen.

Custom splash screen defined in Manifest