refactor(notifications-tab/badge): use improved implementation

Removes the now unecessary network call, by hooking into the notification reciever instead.

mastodon/src/main/java/org/joinmastodon/android/PushNotificationReceiver.java

@@ -76,6 +76,8 @@ public class PushNotificationReceiver extends BroadcastReceiver{
 									@Override
 									public void onSuccess(org.joinmastodon.android.model.Notification result){
 										MastodonAPIController.runInBackground(()->PushNotificationReceiver.this.notify(context, pn, accountID, result));
+										GlobalUserPreferences.unreadNotifications = true;
+										GlobalUserPreferences.save();
 									}
 
 									@Override