With SDE-1447 we're deploying the hive-operator as a part of ARO in Azure.  To support this deployment we need the ability to override the installer used by hive to provision a cluster, as ARO has a fork of upstream OCP installer that carries patches / fixes specific to how we deploy ARO clusters.

CIS used to have this before the installer image was bundled in the OCP release.  We're asking for the field to be added back in some form where if an installer image is specified in CIS that it's used instead of the installer in the release image. 

We recognize the ideal scenario is to upstream everything we carry but we're not there today.  It is taking time to get that done.