Settings: fix a couple of multiuser bugs

- show interface settings
- hide media scan on boot behaviour
- show privacy guard

for other users

Change-Id: I2b488f69b820f289d7ddb04e5171637b355dc5cf
packages: settings: CryptKeeper: Disable FDE if PFE activated

Don't allow Full-Disk-Encryption (FDE) after Per-File-Encryption (PFE)

Change-Id: I5ed46d4362f6536a6cf526aa5bf4bac4610c47b6
Settings: Add proximity wake option

Ports and combines:

http://review.cyanogenmod.org/#/c/66658/
Settings : Add preference for proximity wake

http://review.cyanogenmod.org/#/c/69347/
Proximity Wake-Up : adjust strings

http://review.cyanogenmod.org/#/c/69803/
Settings : Make proximity opt-in

Change-Id: Iea0853eccf764438c7aaac76afd13c364fcea0ec