Rename KEY_VOICE_PRIVACY_DISABLE_BOOL -> KEY_VOICE_PRIVACY_DISABLE_UI_BOOL

Disabling voice privacy sounds scary. Update this config variable name
to what it actually does, which is to hide some settings UI.

Bug: 21571894
Change-Id: Ib981b5e442b56d0167a19326fe34935b7a1cfbf1
3 files changed