Starting Q3 2015 the commit rate of this central Android component dropped significantly. See https://github.com/android/platform_frameworks_base/graphs/contributors<p>What happened?
Not sure. Several of high change frequency components from telephony were moved to platform/packages. Also Google has probably not dumped the latest changes yet.
Google Play Services (a closed source, Google-copyrighted component) has been slowly eating more and more of the stuff that was previously handled by AOSP.