Hide resume players on entering the lockdown mode

Don't add the resume player when onNotificationRemoved due to entering
the lockdown mode. The media keeps playing and the resume player should
not be visible.
Hides media carousel on entering lockdown mode.
Tracks when the keyguard is gone to make sure media carousel is visible.

Bug: 253335072
Test: atest MediaDataManagerTest.
Test: atest MediaCarouselControllerTest.
Change-Id: I5d4ed30a24f43db984d73c58bbc551a0ec89509c