Move volume adjust sound option to more native place (1/2).

Our new UX concept includes saving more settings headers possible.
Move this into Volumes settings fragment. Also update description string.

Change-Id: Icee918dc35a4248e4dcdb4c9aa6af9d2ff68f220
Signed-off-by: Carlo Savignano <stevewatersy@gmail.com>
Merge remote-tracking branch 'PA-base/kitkat' into kitkat-remix