Implement visitUris for RemoteViews ViewGroupActionAdd.

This is to prevent a vulnerability where notifications can show
resources belonging to other users, since the URI in the nested views
was not being checked.

Bug: 277740082
Test: atest RemoteViewsTest NotificationVisitUrisTest
Change-Id: I5c71f0bad0a6f6361eb5ceffe8d1e47e936d78f8