Revert "Remove the navigation camera icon in keyguard if disabled by DPM"

This reverts commit 6eef309ae2e85e96f276b18a4f989f2086e2cf9c. The camera
widget itself not showing is a bug with the lock screen. The navigation
icon should be displayed.

Change-Id: If6edf7e70f48a1b272d336e9a9245095af10b38f