Disabling Android O auto-fill service for an application

Currently there is no direct way to disable the autofill for an entire application, since the autofill feature is View specific.

You can still try this way and call BaseActivity everywhere.

public class BaseActivity extends AppCompatActivity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
       super.onCreate(savedInstanceState);
       disableAutofill();
    }

    @TargetApi(Build.VERSION_CODES.O)
    private void disableAutofill() { 
        getWindow().getDecorView().setImportantForAutofill(View.IMPORTANT_FOR_AUTOFILL_NO_EXCLUDE_DESCENDANTS);
    }
}

You can also force request autofill this way.

public void forceAutofill() {
    AutofillManager afm = context.getSystemService(AutofillManager.class);
    if (afm != null) {
        afm.requestAutofill();
    }
}

Note: At the moment autofill feature is only available in API 26 Android Oreo 8.0

Hope this helps!