Comment by bsimpson

I haven't open sourced anything in a while, but at Google it's historically been pretty easy so long as you let Google put itself as the copyright holder and aren't in any legal minefields (e.g. emulators). You can actually look up the Google Open Source docs even if you don't work there.

That's why so many repos say "Not an official Google product." That's the boilerplate of someone's side project that got open sourced, but Google wanted to claim copyright.