Cluster-samples-operator: role reads all secrets in openshift-config, not just pull-secret

A flaw was found in the cluster-samples-operator. The RBAC Role coreos-pull-secret-reader in namespace openshift-config grants get, list, and watch permissions on all Secret resources without resourceNames scoping. The operator only requires access to the pull-secret Secret. If the samples-operator pod or its service account token is compromised through a separate vulnerability, an attacker could read all secrets in openshift-config, potentially including OAuth identity provider credentials, cloud provider credentials, and other sensitive cluster configuration.