Adding Timer times-up notification

Bug: 7498098
Bug: 7564768

Complies with Section K of wireframes with the agreed exceptions:
(1) Show "Done" instead of "Stop" when timer is delete after use
(2) Clicking on stop does not launch DeskClock
Features to QA:
- Updating label, updates notification
- Selecting +1m when desk clock not running updates the in-use notification
- Times-up notifications appear if and only if the Timer Buzzing Activity is not shown
- Selecting +1m or Stop(or Done) updates the desk clock timer tab

Change-Id: Ia27f86ad6ba1a3bdba50403a6fdb86208f911637