OSDOCS-9379:adding IAM permissions

Author: brendan-daly-red-hat

modules/minimum-required-permissions-ipi-gcp.adoc

@@ -182,7 +182,9 @@ If your organization’s security policies require a more restrictive set of per
 .Required IAM permissions for installation
 [%collapsible]
 ====
+* `iam.roles.create`
 * `iam.roles.get`
+* `iam.roles.update`
 ====
 
 .Required permissions when authenticating without a service account key