Allow 2-pane deep link to access unexported Activity

If an Activity is not exported, the Activity still can be
launched by components of the same application, applications
with the same user ID, or privileged system components.

Bug: 261678674
Bug: 250589026
Change-Id: I89b2ae49b3b13f29b0a02cd54291937241f61696
Merged-In: I662df6cb287361b135e2c596abe946ddeb03bda4
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>