title: Android: NullPointerException on NetworkInfo.isConnected() with Firebase
body: <p>Sometimes, on different mobiles (Android 7) there is this crash:</p>
  
  <pre><code>Fatal Exception: java.lang.RuntimeException: Error receiving broadcast Intent { act=android.net.conn.CONNECTIVITY_CHANGE flg=0x4000010 (has extras) } in com.google.firebase.iid.zzae@3c68978
         at android.app.LoadedApk$ReceiverDispatcher$Args.run(LoadedApk.java:1178)
         at android.os.Handler.handleCallback(Handler.java:751)
         at android.os.Handler.dispatchMessage(Handler.java:95)
         at android.os.Looper.loop(Looper.java:154)
         at android.app.ActivityThread.main(ActivityThread.java:6321)
         at java.lang.reflect.Method.invoke(Method.java)
         at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
         at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)
  Caused by java.lang.NullPointerException: Attempt to invoke virtual method 'boolean android.net.NetworkInfo.isConnected()' on a null object reference
         at com.google.firebase.iid.zzad.zzchr(Unknown Source)
         at com.google.firebase.iid.zzae.onReceive(Unknown Source)
         at android.app.LoadedApk$ReceiverDispatcher$Args.run(LoadedApk.java:1163)
         at android.os.Handler.handleCallback(Handler.java:751)
         at android.os.Handler.dispatchMessage(Handler.java:95)
         at android.os.Looper.loop(Looper.java:154)
         at android.app.ActivityThread.main(ActivityThread.java:6321)
         at java.lang.reflect.Method.invoke(Method.java)
         at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:886)
         at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:776)
  </code></pre>
  
  <p>Have you seen this error before? I don't know how to correct this bug...</p>
  
  <p>Thank you very much guys!</p>