title: FirebaseInstanceId.getInstance().getToken() without using Default FirebaseApp
body: <p>I´m trying to use FCM to send Firebase Notifications, but I have a Application using one Firebase Project and a library using another Firebase Project. I want to receive the token from library Firebase Project to receive Firebase Notifications.</p>
  
  <p>When I try directly receive the token using:</p>
  
  <pre><code>FirebaseInstanceId.getInstance().getToken();
  </code></pre>
  
  <p>I received a valid token, but from Application Firebase Project. If i try to force in <code>getInstance()</code> the library Firebase Project, using:</p>
  
  <pre><code>FirebaseInstanceId.getInstance(FirebaseApp.getInstance("ABC")).getToken();
  </code></pre>
  
  <p>I receive <code>null</code>. If I try to use Application or Library Firebase Project passing parameters in <code>getToken()</code> as:</p>
  
  <pre><code>FirebaseInstanceId.getInstance().getToken(getApplication().getResources().getString(R.string.gcm_defaultSenderId), FirebaseMessaging.INSTANCE_ID_SCOPE);
  </code></pre>
  
  <p>or</p>
  
  <pre><code>FirebaseInstanceId.getInstance(FirebaseApp.getInstance("ABC")).getToken(getApplication().getResources().getString(R.string.gcm_defaultSenderId), FirebaseMessaging.INSTANCE_ID_SCOPE);
  </code></pre>
  
  <p>I received the same valid token from Application Firebase Project.</p>
  
  <blockquote>
    <p>the <strong>R.string.gcm_defaultSenderId</strong> is from library project resources</p>
  </blockquote>
  
  <p>There is another way to receive Library Firebase Project token or I'm doing something wrong?</p>