Doesn't Google Play Services update in the background without warning? There's never a update notification for it but it still gets updated somehow. I found this information online for Google Play Services and it sounds like it could have the power to control something like battery saver.
"Google Play Services is used by almost all Google apps and has system-level powers to provide multiple internal features. All major Android services are controlled by Google Play Services. Without this, Apps may not work properly."
"Google Play Services is automatically updated through Google Play on devices running Android 4.0 or newer. This means Google can do fast, silent rollouts of updates, providing new functionality to older devices without manufacturers having to update the Android firmware itself, working around the fragmentation of the platform for which it had become infamous."
There's also a Google Play Services Beta program, so maybe they accidentally rolled out a experiment they wanted test on beta users, to everyone. I still would like Google to explain more but I just wanted to share my thoughts on the subject.