Fix shouldControlUnlockedScreenOff.

This was currently returning true and starting the animation even if
DozeParameters#canControlScreenOff is false. This resulted in
inconsistent state when AOD was disabled, which resulted in blank
screens if the screenoff animation is interrupted.

Fixes: 219043099
Test: atest SystemUITests
Test: atest PlatformScenarioTests:android.platform.test.scenario.sysui.lockscreen
Change-Id: Id0a3d4ad48ff48175e23b2b31315a156cacad503