Adds dynamic summary getter in relevant BasePreferenceControllers.
Preferece controllers that don't have dynamic summaries or which
are not yet BasePreferenceControllers are not changed right now.
Change-Id: I435ccab7758d90515583fd8ca10a9b1ef0c858b9
Fixes: 71514936
Test: robotests
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
