openshift-install create manifests enables users to override default manifests for clusters at install time.

Given that the image registry operator config already supports BYO KMS key via config (.spec.storage.s3.keyID; API reference), it should be possible for users to provide a KMS key at day-0 by overriding the image registry operator config before provisioning a cluster.

The outcome of this spike to validate whether the above is feasible, and if so to provide a step-by-step guide to set up a customer provided KMS key id for the registry at install time.