Settings: Restart existing volumizers in volume prefs.

Use the new .start() method to ensure the underlying volumizer
is always started, regardless of pref activity lifecycle.

Depends on frameworks/base:
  I2f860864161f818d5a62a28331ef1c47051fb39f

Bug:17898190
Change-Id: I55dea590c13363730549aa29f194337efccdeaf7