DeskClock: Remove FAB from ExpiredTimersActivity

* Since every timer has an own stop button, we don't need a common
  one for all of them.
* Also, the behaviour is non deterministic: Button on each timer
  just stops it, FAB removes all of them

Change-Id: I4c9ddea9fe45b39ec46e22bb22ea44dd7bfff87f
2 files changed