Bug 1476596 - Prevent Stumbler notification being shown after reboot. r=jchen

Because of the START_STICKY flag, upon boot completed, the service
would be started by the system which would trigger onStartCommand
and the notification being shown on Android Oreo+ devices without
a following call to onHandleIntent.

MozReview-Commit-ID: EldSSzRb7Zd

--HG--
extra : rebase_source : 2f39e499b744188e48adbdf03e426d9d50c45262

mobile/android/stumbler/java/org/mozilla/mozstumbler/service/stumblerthread/StumblerService.java

@@ -152,7 +152,7 @@ public class StumblerService extends PersistentIntentService
 
             startForeground(R.id.stumblerNotification, notification);
         }
-        return START_STICKY;
+        return super.onStartCommand(intent, flags, startId);
     }
 
     // Called from the main thread