Hi,
It has been in use in one Google-maintained app for the last couple of years without known issues. I'm not sure whether external apps have been using it externally - would be interested in hearing the experience from any apps that have. So while it is stable for at least some use cases, I'm not aware of wide-enough usage to be confident that it is production ready for all scenarios.
I would mostly consider using it only if you have an existing, large app that has already integrated with Volley and are interested in improving the threading model / moving to Cronet without having to migrate the full library to something else. If you are writing a new app, you would probably be better off with a newer framework that is seeing more active development. I'm not familiar enough with other libraries to make a strong recommendation, but I am aware that apps have been using Retrofit, ktor (for Kotlin), or Cronet directly and have generally been happy with the results. Or, if you own both the client and server, a higher-level framework like gRPC might be a good choice. We continue to make bug fixes to Volley on an as-needed basis, but are no longer generally developing large features.
Thanks,
Jeff