onError method does not indicate any problems to the user

[davidchesnut]

In the SignInActivity.java file there is an onError handler for signing in that is called when an error occurs. The code does not indicate that anything went wrong, so if there is a problem, the user is returned to the sign in activity with no explanation. Recommend adding a toast.

@Override
public void onError(Exception e) {
   // Recommend add a toast here for the user
    e.printStackTrace();
}