Settings: Migrate stats opt out to global settings.

Control newly introduced global setting

Change-Id: Iea22206cd8ac8bf7d45e4b7dabfb9f0d1e602e0e
(cherry picked from commit bf8e9f15a2138a6c29c84c343408b3acecca150c)
Merge pull request #24 from CyanogenMod/stable/cm-11.0

Settings: Migrate stats opt out to global settings.