Merge changes from topics "nem-combine-callbacks", "nem-fullscreen-intent",...

Merge changes from topics "nem-combine-callbacks", "nem-fullscreen-intent", "nem-interruption-state"

* changes:
  Combines NotificationEntryManager listener interfaces (part 1).
  Moves fullscreen intent logic to NotificationActivityStarter.
  Extracts heads-up/pulsing logic from NotificationEntryManager.