4.12 backport: Disconnected cluster installation fails with pull secret must contain auth for "registry.ci.openshift.org"

Agent based installation is failing for Disconnected env due to pull secret is required for registry.ci.openshift.org. As we are installing cluster in disconnected env, only mirror registry secrets should be enough for pulling the image.

registry.ci.openshift.org/ocp/release:4.12.0-0.nightly-2022-10-18-041406

Always

1. Setup mirror registry with this registry.ci.openshift.org/ocp/release:4.12.0-0.nightly-2022-10-18-041406 release. 
2. Add the ICSP information in the install-config file
4. Create agent.iso using install-config.yaml and agent-config.yaml
5. ssh to the node zero to see the error in create-cluster-and-infraenv.service. 

create-cluster-and-infraenv.service is failing with below error:
 
time="2022-10-18T09:36:13Z" level=fatal msg="Failed to register cluster with assisted-service: AssistedServiceError Code: 400 Href:  ID: 400 Kind: Error Reason: pull secret for new cluster is invalid: pull secret must contain auth for \"registry.ci.openshift.org\""

create-cluster-and-infraenv.service should be successfully started.

Refer this similar bug https://bugzilla.redhat.com/show_bug.cgi?id=1990659