Fix home controls showing on low light dream

Low light should never show complications, so short circuit early and
don't return any in the state controller.

Bug: 277746325
Test: atest DreamOverlayStateControllerTest
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:f501b295e11d22455f661707adad9d020b193d25)
Merged-In: Iae6388dafa69098b70e9229bc562172fec1fb149
Change-Id: Iae6388dafa69098b70e9229bc562172fec1fb149