Having consistent import order will reduce chance of merge
conflict between internal and external master
Test: rebuild
Change-Id: I0b1a170967ddcce7f388603fd521f6ed1eeba30b
Migrates Notification settings (app level, group level, and channel
level) into PreferenceControllers (and most importantly:
PreferenceControllerTest)
Note: this removes the 'Advanced' preference group, but does
not yet use the standard system 'Advanced' grouping as it does
not currently support our use case (where we don't know how many
fields to show outside of 'Advanced' until onResume() and also
where we need fields to show below the 'Advanced' group).
Test: make RunSettingsRoboTests
Change-Id: Iddd1b4771922db322e5f73562e9d63ed077c5396
