Merge changes If1d42a14,I57a5d25e,Id7ce26cb,I2edf746c,I6887c8d6 into main

* changes:
  [Notif] HeadsUpManagerImplTest: Move remaining tests, delete old file.
  [Notif] HeadsUpManagerImplTest: Move showNotif & removeNotif tests.
  [Notif] HeadsUpManagerImplTest: Move "has HUNs?"-related tests.
  [Notif] HeadsUpManagerImplTest: Move compareTo-related tests.
  [Notif] Move sticky-related tests to HeadsUpManagerImplTest.