This will allow us to access it from SystemUI.
Bug: 346519570
Test: builds
Flag: EXEMPT trivial refactor
Change-Id: I5bc480bd4eb0cbf8a26989dd11c064e66e5ee70e
So that when it's moved to SettingsLib, it doesn't need to carry that baggage.
Bug: 346519570
Test: atest com.android.settings.notification.modes
Flag: android.app.modes_ui
Change-Id: I7911a521d96f5dbac2c2395171d324b7b54b8b07
Adds the settings page that a user will reach from a mode settings page
when they tap on "App," to allow them to select whether all, none, or
priority modes can break through and send notifications.
Bug: 308819928
Bug: 331267485
Flag: android.app.modes_ui DEVELOPMENT
Test: build and test, controller unit tests
Change-Id: I5bcebfca0fc2882f839afdced8d2b817dad14e6c