The only thing I heard is that support is coming "next year" but I would guess that it would be something we'll see earlier in the year rather than later.
This is just a guess, though, I don't have any information about this other than what is publicly known (which isn't a lot other than it's coming).
Google, can you just put out Chromium APK that just launches you to the Stadia home page?
I have hunch they might be trying to find more ways to integrate the Stadia controller to do more with Android devices.