title: How to fix FirebaseAuth.instance.currentUser() in flutter app using firebase_auth package? It is always returning null
body: <p>I am using the firebase_auth package to implement the authentication functionality in my flutter application and for auto-login of user I need a response from <code>FirebaseAuth.instance.currentUser()</code> which is always returning null. They have a Github issue <a href="https://github.com/flutter/flutter/issues/17805" rel="nofollow noreferrer">here</a> but it is closed and not have much details.</p>
  
  <p><a href="https://pub.dartlang.org/packages/firebase_auth#-changelog-tab-" rel="nofollow noreferrer">Here</a> is the link to package description. Do I need to migrate my project to AndroidX to make things work?
  Is there any other way to make all of this work without migrating a project to AndroidX?</p>