Remove needing the debug flag; introduce feature flag defaulted on

* Feature level flag that is by default true
* Removes the flag gating activity view; if the notif is properly
  configured it will show as a bubble with activity view

Test: use BubbleSettings.apk to toggle all settings off -> note no bubbles
      toggle settings on -> bubbles

Change-Id: Ia4721250c65557313b872e8972da77eb3b5c5684