title: Issue with app activities flow using Facebook SDK for Android
body: <p>I'm following the Facebook tutorial on how to implement the Facebook Login flow to my Android app. It works fine with UiLifecycleHelper and Session implementations:</p>
  
  <pre><code>private UiLifecycleHelper uiHelper;
  private Session.StatusCallback callback = 
      new Session.StatusCallback() {
      @Override
      public void call(Session session, 
              SessionState state, Exception exception) {
          onSessionStateChange(session, state, exception);
      }
  };
  </code></pre>
  
  <p>In the onSessionStateChange i check if the state is opened and start the MainActivity, and everything works ok.
  My doubt here is: do i have to reimplement this code (UiLifeCycleHelper, onSessionStateChange) on every Activity of my app or not? And if not, how i can control the Facebook Session flow through the activities? </p>