@Override
    public void onResume() {
        logger.fine("onResume");
        super.onResume();

        gainFocus();
    }
When the Fragment resumes (i.e. after app resumes or device screen turned
back on), call the gainFocus() in the jME application.
jme3-android/src/main/java/com/jme3/app/AndroidHarnessFragment.java