If the effects are being muted by a notification listener, display
a "Muted by <x>" msg instead of an active slider inside the
Ring/Notification volume setting pref.
Update volume pref design to optimize for this new custom appearance.
Depends on frameworks/base:
Icdb5f85eb4bcaa1ead7d77c1460e06ad3f0604d5
Bug: 17461563
Change-Id: I6da871e16009370402451a2ff507de4762644a80