profile pic configuration: release camera

fixes CNVS-12086

test plan:
  * enable profiles and avatars
  * open user settings
  * edit profile picture
  * select "take a picture"
  * allow access to your camera
  * leave "take a picture"
  * verify that your camera is no longer in use

Change-Id: I675cb7b71869d55d529f85fce34c028a396d0893
Reviewed-on: https://gerrit.instructure.com/32511
Reviewed-by: Jon Willesen <jonw@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
QA-Review: Steven Shepherd <sshepherd@instructure.com>
Product-Review: Braden Anderson <banderson@instructure.com>