Added support for rollout parameter values in Remote Config Templates. (#923), (#927)
Please note that it's not (yet?) possible to create rollouts programmatically via the Firebase API. This means that you have to manually create a rollout in the Firebase console to be able to reference it in the Remote Config template. Rollout IDs are named rollout_<number>, and you can find the ID in the URL after clicking on a rollout in the list.