Removed emergency info and add user when locked from Users settings.

If new IA is enabled,  Emergency Info and Add user when locked has been moved to
Users & accounts page, so Users page should not show them.

Also fix the issue that update for the add user when locked switch does
not persist correctly.

Change-Id: I26d9f59d0f4bf3fd36a7d07d13f95127b40a8a3e
Fix: 33703736
Test: make RunSettingsRoboTests