Fixes broadcast filtering for multi-user sys apps

This change fixes a bug caused by the assumption that
FIRST_APPLICATION_UID is just that and that we should not treat UIDs
with an APP_ID < FIRST_APPLICATION_UID in secondary users as system
users that can see all packages.

Test: atest AppsFilterTest AppEnumerationTests
Test: manual; enable/disable apps in work profile
Fixes: 157690238
Change-Id: I0aab78954222f0d1cf86a83375a8d0669025144a