Merge pull request #89538 from mletalie/OSDOCS-13534

[OSDOCS-13534] Update guidelines on using constraints/compute.trustedImageProjects org policy constraint

Author: EricPonvelle

modules/ccs-gcp-customer-procedure.adoc

@@ -30,6 +30,9 @@ Although the `EXTERNAL_NETWORK_TCP_UDP` load balancer type is not required when
 ** This policy constraint is supported only if the cluster is created with *Enable Secure Boot support for Shielded VMs* selected during the initial cluster creation.
 * `constraints/compute.vmExternalIpAccess`
 ** This policy constraint is supported only when creating a private cluster with GCP Private Service Connect (PSC). For all other cluster types, this policy constraint is supported only after cluster creation.
+* `constraints/compute.trustedImageProjects policy`
+** This policy constraint is supported only when the projects `redhat-marketplace-public`, `rhel-cloud`, and `rhcos-cloud` are included in the allowlist. If this policy constraint is enabled and these projects are not included in the allowlist, cluster creation will fail.
+
 
 .Procedure