[1/2] OmniGears: Configure headset hook

Whether or not to allo headset hook to launch voice commands

Useful with headset control programs

PS3: Whitespace
PS4: Rebase
PS5: android:persistant

Change-Id: I48f9f9853987b30038360472c140b33e2b2f5d2a
Merge pull request #1 from omnirom/android-4.4

[1/2] OmniGears: Configure headset hook