Move full screen intent decisions to HeadsUpCoordinator

The actual handling to launch the full screen intent remains in StatusBarNotificationActivityStarter.

This adds a provider class because StatusBarNotificationActivityStarter and HeadsUpCoordinator are in different scopes. The provider class receives the decision to launch a full screen intent and passes it along to listeners for that event (in practice just StatusBarNotificationActivityStarter).

Bug: 248325248
Test: HeadsUpCoordinatorTest, StatusBarNotificationActivityStarterTest, manually verified that at least a regular full screen intent works
Change-Id: I2e8e81bc617b2819cbdf82fcc460d5ec931a572a