TextClock registerContentObserver with UserHandle

When adding a widget that uses TextClock to the home screen from a work
profile, the home screen may crash due to a
android.permission.INTERACT_ACROSS_USERS permission error, due to a
mismatch between the caller's userId and the widget's userId.
This fix uses the caller's userId to register the ContentObserver.

Bug: 111627637
Test: added a widget (as specified in the bug) that uses TextClock from a work profile
Change-Id: I153e55b755d656f1d7882645df15290bf8ad56f9