Suppress private_endpoint_subnetwork when master_ipv4_cidr_block is set

mmv1/third_party/terraform/services/container/resource_container_cluster.go.erb

@@ -1684,7 +1684,7 @@ func ResourceContainerCluster() *schema.Resource {
 							Optional:     true,
 							ForceNew:     true,
 							AtLeastOneOf: privateClusterConfigKeys,
-							DiffSuppressFunc: tpgresource.CompareSelfLinkOrResourceName,
+							DiffSuppressFunc: containerClusterPrivateClusterConfigSuppress,
 							Description: `Subnetwork in cluster's network where master's endpoint will be provisioned.`,
 						},
 						"public_endpoint": {
@@ -6387,6 +6387,10 @@ func containerClusterPrivateClusterConfigSuppress(k, old, new string, d *schema.
 		return suppressNodes && !hasSubnet
 	} else if k == "private_cluster_config.#" {
 		return suppressEndpoint && suppressNodes && !hasSubnet && !hasGlobalAccessConfig
+	} else if k == "private_cluster_config.0.private_endpoint_subnetwork" {
+		// Suppress diffs in private_endpoint_subnetwork when master_ipv4_cidr_block is set
+		_, hasMasterCidr := d.GetOk("private_cluster_config.0.master_ipv4_cidr_block")
+		return hasMasterCidr || tpgresource.CompareSelfLinkOrResourceName(k, old, new, d)
 	}
 	return false
 }