Fix auto-brightness in doze

- AutomaticBrightnessController was incorrectly disabling auto-brightness in doze even if the config allowed it.

- We should rely on the policy and not the display state - when we enter doze, the first power request has policy DOZE but the display state is still ON.

Bug: 322974128
Bug: 304339170
Test: atest DisplayPowerControllerTest
Test: atest AutomaticBrightnessStrategyTest
Test: atest AutomaticBrightnessControllerTest
Change-Id: Ie04184b6cca91c9a96c360d72fbbf59cfb8ecf59