title: Flutter GoogleSignIn java.lang.NoClassDefFoundError: Failed resolution of: Landroidx/lifecycle/LifecycleEventObserver
body: <p>Trying to setup social login in Flutter App using GoogleSignIn and facebookSignIn via Firebase-auth I'm getting this error : </p>
  
  <pre><code>java.lang.NoClassDefFoundError: Failed resolution of: Landroidx/lifecycle/LifecycleEventObserver
  </code></pre>
  
  <p>I'm using thoses packages : </p>
  
  <pre><code>flutter_facebook_login: ^3.0.0
    google_sign_in: ^4.0.14
    firebase_auth: ^0.15.1
  </code></pre>
  
  <p>With <strong>flutter 1.9.1 + hotfix.6</strong></p>