Specifies the release track to which the given app file(s) will be re-assigned.
You can enter the name of a
custom
track, or one of the built-in tracks:
- internal
- alpha
- beta
- production
For these tracks, you have the choice of rolling out the uploaded app files
to all existing users immediately, or doing a staged rollout so that only
a percentage of your existing userbase will be able to download the new version.
For more information on using the internal, alpha, beta or custom testing tracks,
see the Google Play documentation:
https://support.google.com/googleplay/android-developer/answer/3131213
This field supports substituting environment variables in the form
${SOME_VARIABLE} or $SOME_VARIABLE at build time.