* Don't keep Settings observers longer than start-stop.
* Only call updateState() once on controllers during create->start->resume.
* Remove some duplicate controller update methods from ZenModesFragmentBase (we can directly call DashboardFragment's).
* Don't update controllers if unrelated modes were changed.
* Extract ZenSettingsObserver for use in the link tile later.
* Add tests.
Fixes: 353946788
Test: atest com.android.settings.notification.modes
Flag: android.app.modes_ui
Change-Id: I64b51714d699b5c3a592a76fcb615d2999998829
This mostly continues to use the existing dialogs in settingslib (ZenDurationDialog, SettingsEnableZenModeDialog) and creates a controller to read from the settings value.
Also updates the "turn on / turn off" button to respect the preferred duration.
Flag: android.app.modes_ui
Bug: 343444249
Test: ZenModeButtonPreferenceControllerTest, ManualDurationPreferenceControllerTest
Change-Id: I2fd49a79d9a5807fefdd7ec310a6cc60d70f9bb1
