The Android community has already adopted it pretty significantly (join the #android Kotlin slack and see for yourself).

And this was done without any official support for Google because... it's not necessary: Kotlin works out of the box. Which is one of Kotlin's strengths.

I am in that slack channel.

Do you have any adoption numbers though ? From what I see in the local companies, kotlin is still very rare, except for a couple of startups (which makes them very attractive tbh). That anecdotal evidence of course and I would love to see a tide change but hard numbers would be an huge help.