Ensure package context used by System UI has a valid userId.

Fixes: 189924598
Bug: 194356170
Test: atest SystemUITests
Test: atest android.service.notification.StatusBarNotificationTest#testGetPackageContext_worksWithUserAll
Change-Id: Ic43a0301cb62ab27e276c2938012a27c3a9a6fff
2 files changed