Is there a way to activate Android picture in picture in Unity Android builds?
This… Makes no sense.
Go read the Google developer pages and identify the OS requirements and the actual steps that need to happen (at the Google API level) for picture-in-picture. It will not be directly available from Unity, but if you identify the steps, most likely you will be able to write a script using this set of API calls:
You probably will also need to craft a few pre- or post-build steps to insert permissions into the AndroidManifest.xml, but that’s just a guess.