* No need to call updateState() in onPreferenceChange()
Bug: 274326713
Test: make RunSettingsRoboTests ROBOTEST_FILTER="(AccessibilityButtonGesturePreferenceControllerTest|CaptioningLocalePreferenceControllerTest|CaptioningFontSizeControllerTest|CaptioningTypefaceControllerTest|AccessibilityButtonLocationPreferenceControllerTest|FloatingMenuSizePreferenceControllerTest|SelectLongPressTimeoutPreferenceControllerTest)"
Change-Id: I14a87597a44c5500ff7e676664b67feb9c352494
1. Add gesture preference controller for gesture navigation
2. Auto update the preview illustarion when screen reader is on
3. Auto update accessibility button title for system navigation
Bug: 190563948
Test: make RunSettingsRoboTests ROBOTEST_FILTER=AccessibilityButtonGesturePreferenceControllerTest ROBOTEST_FILTER=AccessibilityButtonPreviewPreferenceControllerTest ROBOTEST_FILTER=AccessibilityLayerDrawableTest ROBOTEST_FILTER=AccessibilityPreferenceControllerTest ROBOTEST_FILTER=AccessibilityButtonFooterPreferenceControllerTest
Change-Id: Ifa98fc029430d86d3143133b3203b239340f2e41