The state of the preference doesn't change until after we get the
callback.
Test: ZenModePrioritySendersPreferenceControllerTest
Flag: android.app.modes_ui
Fixes: 337079247
Change-Id: I1c98561de89e9398f26300bb14710f18991f78f4
Also fixed a handful of style issues / warnings along the way.
Fixes: 341950853
Fixes: 341910620
Test: atest com.android.settings.notification.modes
Flag: android.app.modes_ui
Change-Id: I65900941fcdf53824caf052fd0a24401c1bfb476