title: Firebase and new Google Sign-In on Android
body: <p>I'm trying to add support for the <a href="https://developers.google.com/identity/sign-in/android/" rel="noreferrer">new Google Sign-in</a> announced as part of Play services 8.3.0. 
  I successfully configured the project and I'm getting a token from the GoogleApiClient, but Firebase is returning an
   <code>Invalid Credentials error</code>
   when calling 
  <code>ref.authWithOAuthToken("google", token)</code></p>
  
  <p>Google+ sign-in is working but that requires a separate permission which is a pain when developing for Marshmallow.
  <a href="https://www.firebase.com/docs/android/guide/login/google.html" rel="noreferrer">Firebase android tutorial</a> has a Google+ sign-in sample and my feeling is that they dont' have support for the new Google Sign-In yet.    </p>
  
  <p>Has anyone tried the new Google Sign-In in connection with Firebase and got it to work?</p>