It's in Google play services, which is "separate" from Android, but good luck installing your favorite Android apps without it.

Most of what you use in Android is closed source, Google apps, blobs, Google Apis, Play Store, Play services...

are you spending the time? nobody is. all the players are not the "users"

also, most of the claim seems to be for code in the very closed source google play services (wildly guessing from the features involved)