FragmentInjectActivity.kt

public abstract class FragmentInjectActivity extends AppCompatActivity
        implements HasAndroidInjector {

    @Inject DispatchingAndroidInjector<Object> androidInjector;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        AndroidInjection.inject(this);
        beforeOnCreate(); // <-- expose here for child to do things before onCreate
        super.onCreate(savedInstanceState);
    }

    protected abstract void beforeOnCreate();

    @Override
    public AndroidInjector<Object> androidInjector() {
        return androidInjector;
    }
}