Hide "Volume adjustment sound" option on non-voice capable devices

On non-voice capable devices, there's no sound when adjusting the
notification volume. Remove the obsolete option from Settings.

Change-Id: I3fc9ef737eb55d591a4ecc7d79ee60b9151395b5
Settings: Remove lockscreen options from security.

  - Create a separate fragment for Lockscreen settings
  - Move App Security up in Security Settings
  - General clean up

Change-Id: I4dc20942b87c2446c7e798e28f7e475efebaddb8