title: Verify Firebase Token at Google App Engine
body: <p>I am developing an Application at Google App Engine. I am using Cloud Endpoints for the communication between an Android App at my Backend at Google App Engine. The Android client uses Firebase Authentication and sends with every call the Firebase token the Cloud Endpoints. </p>
  
  <p>At Google App Engine I use the following code to verify the Firebase Token. I am using the Firebase Admin SDK 4.0.3</p>
  
  <pre><code>Task&lt;FirebaseToken&gt; authTask = FirebaseAuth.getInstance().verifyIdToken(token);
  
  try {
      Tasks.await(authTask);
  } catch (ExecutionException | InterruptedException e ) {
      log.severe(e.getMessage());
  }
  FirebaseToken decodedToken = authTask.getResult();
  </code></pre>
  
  <p>The execution of the Task is running at a Google App Engine Backend Task but unfortunately this Backend instance does not shutdown and so I exceed my free quota limit. So can someone give me a hint how I can shutdown the Backend Instance after Token verfication?</p>