Migrate "duration for quick settings" to new modes page.

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