The material design of the request has removed this option from
the dialog, and now needs to be in settings. When screen
pinning is off it shows a description of how to use the feature,
however when on it shows a switch to control whether it locks
the device on exit. This setting defaults to on if there is a
lock pin/pattern.
Bug: 16957435
Change-Id: I59e0d64964cee4302e6ecff59e622cfe11422807
