Use context's userId in ContentResolver class.

When registering and notifying observers, we should use the user in the
context as opposed to current user.

Fixes: 32955100
Test: runtest -x core/tests/coretests/src/android/content/CrossUserContentResolverTest.java
Change-Id: Idc169d6cc1ec0cea40a736b87c12d4609f1de9c7
6 files changed