cmstats: Remove preferences and always enable stats

 * Not having an accurate count of how many people are using CM is
   painful. I am making an executive decision to remove the opt-out and
   always turn stats on. The data is anonymized and there is nothing
   evil that can be done with it. The only purpose here is to tell us if
   we are a successful project or not.

Change-Id: I915c5e824d4e15c05feb37a3d8ed911464b5d61b
Settings:merge CyanogenMod

Change-Id: I909dc0aeb27ecb685ca1c6e832441a70d9f74780