Android - Detect long press Power Button

Hi guys,
I followed many guides on web to detect the long press of the Power Button which show you the device-off confirmation window, but nothing seems to work. I used onKeyDown to start tracking and onKeyLongPress with the specific keycode but they doesn’t seem to be called as well. Do you have any suggest?

@Override
  public boolean onKeyDown( int keyCode, KeyEvent event ) {
    if( keyCode == KeyEvent.KEYCODE_POWER ) {
      event.startTracking();
      return true; 
    }
    return super.onKeyDown( keyCode, event );
  }

  @Override
  public boolean onKeyLongPress( int keyCode, KeyEvent event ) {
    if( keyCode == KeyEvent.KEYCODE_POWER ) {
      //Handle what you want in long press.
    	UnityPlayer.UnitySendMessage("Pfb_GameControl","PauseGameFromNative","");
      return true;
    }
    return super.onKeyLongPress( keyCode, event );
  }

Just do this…

void OnApplicationFocus(bool focusStatus) {
	if(focusStatus == true){
		//user returned to the game
	}else{
		//power button was long pressed
	}
}