Stop showing RESTRICTED toast for new restriction.

The RESTRICTED bucket isn't clear from the notification restriction
option, so it'll be surprising for users to see the toast if they ask
the system to restrict the app. Don't show the Toast if the user tries
to restrict an app via the system's posted notification.

Bug: 217964313
Bug: 220897723
Test: Android builds
Change-Id: Ia86f5d6aa9ca4778395dde2834b2dd30cfc123a3