Add ro.pa property, used by ParanoidOTA

Patch Set 2:
Move the property to pa_overrides.mk

Change-Id: I8e59ab044a4fc1bda9b35a13bdc3a722b3a23dc3
Merge "Add ro.pa property, used by ParanoidOTA" into kitkat
Merge remote-tracking branch 'PA-vendor/kitkat' into kitkat