Reset mSecureCameraLaunched when bouncer is shown

Whenever the bouncer is shown, face auth should start again.

Fixes: 137228869

Test: Install test camera app that's available on lockscreen, double tap
      power to launch camera on lock screen. Bouncer is shown, and face
      unlock works

Change-Id: Ia33075935c6d8413ab7c9351739cca67bb81c377