Skip killing backup app on notification deny in PermissionController

The permissioncontroller handles permission backup and restore, so it
must skip the killing of an app if the permission is POST_NOTIFICATIONS,
the app is a backup and restore app, and a restore is currently in
progress.

Bug: 230758495
Test: manual
Change-Id: I2908beaaca9fa8b0a467836f839bc917bb06f078