Setting to change sysui theme

Users now can manually pick if they want light or dark QS
and launcher

Change-Id: Ic0a43bc5e8777c39bfe5c0bbc606bf6be20f7168
Fixes: 63903361
Test: make RunSettingsRoboTests ROBOTEST_FILTER=SystemUiThemePreferenceControllerTest
Test: manual
5 files changed