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
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:850fd984e5f346645b5a941ed7307387c7e4c4de)
Merged-In: I5c71f0bad0a6f6361eb5ceffe8d1e47e936d78f8
Change-Id: I5c71f0bad0a6f6361eb5ceffe8d1e47e936d78f8