code: @Override
      public void onTokenRefresh() {
          Intent intent = new Intent(ACTION_REFRESH_PUSH);
          LocalBroadcastManager.getInstance(getApplicationContext()).sendBroadcast(intent);
      }
docs: Called if InstanceID token is updated. This may occur if the security of
  the previous token had been compromised. Note that this is also called
  when the InstanceID token is initially generated, so this is where
  you retrieve the token.