Fix nondeterminism in NotificationLockscreenUserManagerTest due to use of a real looper

* Adds a Rule that exposes handling of Log.wtf in a way that is safe for tests
* Adds a mockExecutorHandler method which allows using FakeExecutor when testing classes that take Handler

Fixes: 313999630
Test: atest NotificationLockscreenUserManagerTest
Flag: NA
Change-Id: I3eafe50af9fe26286c955c9aa5aa408142cf1dba
5 files changed