Alby extension is available for firefox and it also supports chromium-like browsers, too. I was able to try it without google login in one of the more privacy-oriented browser for my experiments. However, I still have not tested the setup on android mobile, so good to know that it is not straightforward process.
So far only Firefox supports plugins like Alby on mobile, it's the same as any other plugin there.
Hopefully in the future there will be more such tools!
Can Alby be used for third-party login window on Mobile applications?!