Settings: adapt lock screen visualizer toggle

 * Do not show the Visualizer toggle for Screen lock : None
 * Show the Visualizer toggle for Screen lock : Swipe
 * Add a missing key field (Screen lock : Swipe)

Change-Id: I460693201142f0d7d5eb34dea91f4f5db33a00d4
Signed-off-by: AdrianDC <radian.dc@gmail.com>