[3/3] Settings: Audio Themes Support
from: https://gerrit.omnirom.org/#/c/5245/

PS 2&3: Update author
PS4: Rebased & fix spaces
Ps5: Move the preference under System sound header

change-Id: I6a92e4c9173be6f6ce31e8555902ea36e05bb82f
Create SoundPack in SD Card if not exists

PS2: Fix whitespaces and tabs

Change-Id: Icebe965f7ff2bc1b52657ff7045c169109740725
Signed-off-by: hany <hany.alsamman@gmail.com>