Remove UPDATED_SYSTEM_APP from updated system apps no longer exist

This address an issue where getPkgState().isUpdatedSystemApp() remains
true even if the apk on /system is removed during OTA.

With this change, it sets updatedSystemApp to false when revoking
system privileges before re-scanning an apk on /data for updated
system apps no longer exist.

Bug: 265752747
Test: Manually tested
  1. Install an app on /product
  2. Update the app
  3. Delete the apk on /product and reboot
  4. Make sure FLAG_UPDATED_SYSTEM_APP removed
Change-Id: I9d9136ac19326599a20afd4710afdaf904572cb2