The source code responsible for doing the color extraction and theming of media notifications on Android versions from 8.0 to 10 is located here, but I couldn't find the code that does a similar function with the Quick Settings integrated media playback sessions on Android 11 (that is similar but not identical, I tried using a media player app on Android 9 and 11 emulators and it looks different on Android 11). I tried searching on cs.android.com (Android code search) but it looks like that I can't search within specific tags or older branches.
Where is the source code of the Quick Settings media session color extraction (from album art/thumbnail) on Android 11 located? I want to know how this works.
Here are screenshots of this in action, from the open source NewPipe app: