Bugfix: PIN keyguard is clipped in Car

  Car is a multi-user system.  There's a cancel button on the Keyguard
  that allows the user to cancel the Keyguard to go back to user
  switcher.  Because different user may have different security mode,
  the container must be resized when the security mode changes.  The fix
  is to destroy the old bouncer view on cancel.

  Screenshot of clipped view: https://screenshot.googleplex.com/0VWdDtrLkAr

Fix: 79202566
Test: In the head unit
Change-Id: Ife33c53785ed96778f08c8f5886885e2b9d29749