Send correct UID on perm flag update

Ensure that the correct per-user UID (not the appId) is used when
notifying permission change listeners of a permission flag update.

Fixes: 145945426

Test: In a secondary user, navigate to the permission groups page of a
pre-M application, and grant or revoke a permission. The permission UI
should update upon backing out of the App Permission Screen.

Change-Id: If540a5e87f915a7cc6aa400b33aa178c2e30f5b9