[CS] Move LkscrnShadeTransitionCtlr to ShadeInteractor#isShadeEnabled.

This also removes the disable-flag-related methods in
CentralSurfacesImpl because #isShadeDisabled was the last one.

Having CentralSurfacesCommandQueueCallbacks store the disable flags
isn't ideal, but rehabbing that class is out of scope for now.

Fixes: 287076786
Test: manual: Verify LockscreenShadeTransitionController gets updated
disable values. If shade is disabled, verify you can't open the shade
from lockscreen
Test: manual: Verify CentralSurfacesCommandQueueCallbacks still gets
disable flags updates and passes them to controllers appropriately
Test: atest ShadeInteractorTest LockscreenShadeTransitionControllerTest
CentralSurfacesImplTest CentralSurfacesCommandQueueCallbacksTest

Change-Id: I529a870b5fabdab9eb614df8bfa2d02fb60de8b6