As of today Google released a new track to publish your apps to called internal. This track will make the app available much faster than the alpha track and it would be super, super awesome if the step supported it.
This link shows the internal test as part of the available tracks.
Use case / for what or how I would use it
Supporting this would allow us to team-check new builds much faster!
I would be more than willing to do a PR. Do you guys have some guidelines on how to setup the steplibrary and everything so that I can easily test it locally ?