The setting has little to no meaning when AOD is on.
Test: make
ROBOTEST_FILTER=AmbientDisplayAlwaysOnPreferenceControllerTest
RunSettingsRoboTests -j
Bug:62391405
Change-Id:If5492227755ca81ec0bcf921a81e2bfd33a85b9c
Adds a setting for controlling always-on ambient display
until the new ambient display settings screen is implemented.
Also updates DozePreferenceController to use the the
AmbientDisplayConfiguration helper instead of recreating that
logic.
Also adds tests for both doze preference controllers.
Bug: 33279975
Test: Toggle "Settings > Display > Always on", verify ambient display is on / off
Test: make RunSettingsRoboTests
Change-Id: If36356bc29329a4e0732e79db662ffb02c9fc189