The original CL just collapsed the panel. Instead, we're using the
dedicated startActivityDismissingKeyguard to make sure the Keyguard
gets properly dismissed first.
Follow-Up-To: I66ebcb66c898dfebe1d09b798f750f696c360da8
Bug: 27790403
Change-Id: I41c02221de951df885ecfb4f2869820b38410f18