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: I9d4356700c6595cbd9c527a08daa63d3fe70e8ce
Merge "Settings: Remove "Make pattern visible" regardless." into pac-4.4