Stats: track how frequently contact images are present incall

For retail devices (and installer builds), introduce tags to be read
by a separate, additional, package.

This will not be read or collected in any community (nightly/M/etc) or
self-built build.

Change-Id: I7f52f18a53ade50e0274af633cb7c26566332ee7
Merge branch 'cm-11.0' of https://github.com/CyanogenMod/android_packages_apps_InCallUI into cm-11.0