title: How to stay logged in after firebase phone authentication?
body: <p>Firstly, pardon me if this a newbie question I am new to Android development.</p>
  
  <p>I am building an app that has phone verification as the only authentication needed. I want the users to stay logged in once they create an account, until they explicitly call <code>FirebaseAuth.getInstance().signOut();</code></p>
  
  <p>Is this possible? If so, how can I achieve this? Thank you!</p>