Correct string for left-handed mode

Change-Id: Iee951db7642a487b9ca94f1264b9cd2e2a4390be
Settings: Remove "Make pattern visible" regardless.

  - Previous logic depended on all pattern lock elements to be
    null prior to removing the preferences. Remove them one by
    one if they exist now.

  - PS #3: Add braces.

Change-Id: If34bc305eddda2985b37bd55349e4bb5d9b63154