Honor shared users in visibility calculations

This change allows apps with the same app id to see each other (members
of the same shared uid, for example) and allows apps targetting an app
in a shared uid to see all of its members.

Bug: 136675067
Test: atest AppEnumerationTests
Change-Id: Ic56c3ff56780828af67210a54968ddaba3aff3d1
1 file changed