OmniGears: enhance AppSelectListPreference

Added support for a third button

Change-Id: Ic152913610ec374144cd7a6388fa8f21ed5d0aeb
[2/2] OmniGears: Lockscreen wallpaper

Base: https://gerrit.omnirom.org/5690

Change-Id: I0098b5f9fe03b26c842d50c7760999956c488d2e
OmniGears: Fix detecting if OmniSwitch is available

Remove OmniSwitch settings if app is either uninstalled
or disabled (frozen)

Change-Id: Ia43d8518aa8d5bafdf5c6c64086a23c1a0f12cba
Merge pull request #6 from omnirom/android-4.4

同步自 omnirom android-4.4