- Added a activity-alias pointing to displaySettings as top level setting item. - Refactored all preference logic in DisplaySettings into PreferenceControllers. During fragment onAttach it installs all controllers, and during onResume it updates preference state. Each controller listens to its own preference change event. Bug: 31800242 Test: RunSettingsRoboTests Change-Id: Ibc9bf200c5acce7c4ae9292340822afee27a3a28