message: Hide the notification nag bar after enabling notifications
  and add a bit of documentation around why the notificationsEnabled setting isn't set here.
diff: @@ -135,6 +135,10 @@ const Notifier = {
  const plaf = PlatformPeg.get();
  if (!plaf) return;
  + // Dev note: We don't set the "notificationsEnabled" setting to true here because it is a
  + // calculated value. It is determined based upon whether or not the master rule is enabled
  + // and other flags. Setting it here would cause a circular reference.
  +
  Analytics.trackEvent('Notifier', 'Set Enabled', enable);
  // make sure that we persist the current setting audio_enabled setting
  @@ -168,7 +172,7 @@ const Notifier = {
  });
  // clear the notifications_hidden flag, so that if notifications are
  // disabled again in the future, we will show the banner again.
  - this.setToolbarHidden(false);
  + this.setToolbarHidden(true);
  } else {
  dis.dispatch({
  action: "notifier_enabled",
  