Collpase expanded bubbles when appropriate

Calls collapseStack() when:

  Statusar.animateCollapsePanels()
      (when StatusBar panel itself is not expanded)
  Broadcast: ACTION_CLOSE_SYSTEM_DIALOGS
  Broadcast: ACTION_SCREEN_OFF

Bug: 123631742
Test: manual, using go/bubbles-app
Change-Id: I40c68a7fc1baac102e481bf5f0d06c9c24bcc252