title: Firebase Authentication FirebaseNetworkException: A network error (such as timeout, interrupted connection or unreachable host) has occurred
body: <p>I'm creating an authentication workflow for my android app. I'm allowing users to sign in with username/password and various OAuth providers. I'm validating emails and password so that, I know the information I'm passing to Firebase is valid. I'm using <code>com.google.firebase:firebase-auth:9.6.1</code></p>
  
  <p>When I execute the following code, I get a callback that says the operation not successful with an error.</p>
  
  <pre><code>mFirebaseAuth.signInWithEmailAndPassword(username,password).addOnCompleteListener(this);
  </code></pre>
  
  <p>Callback function or completion listener tells me</p>
  
  <pre><code>com.google.firebase.FirebaseNetworkException: A network error (such as timeout, interrupted connection or unreachable host) has occurred.
  </code></pre>
  
  <p>The username I'm passing doesn't exist yet. So, I would assume to see some kind of error stating the <strong>user doesn't exist</strong>. Am I passing something incorrectly or am I assuming incorrectly? I can also see that in the Firebase documentation, the iOS library has a various error codes common to all API methods section where as the Android section doesn't show this. One of these exceptions is <code>FIRAuthErrorCodeUserNotFound</code>. So, does that functionality even exists in the Android library?</p>