Fixed cluster resource limits maximum to be marked as required in docs. (GoogleCloudPlatform#12777)

Author: mtrqq

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

@@ -628,9 +628,10 @@ func ResourceContainerCluster() *schema.Resource {
 										Description: `Minimum amount of the resource in the cluster.`,
 									},
 									"maximum": {
-										Type:        schema.TypeInt,
-										Optional:    true,
-										Description: `Maximum amount of the resource in the cluster.`,
+										Type:         schema.TypeInt,
+										Description:  `Maximum amount of the resource in the cluster.`,
+										Required:     true,
+										ValidateFunc: validation.IntAtLeast(1),
 									},
 								},
 							},

mmv1/third_party/terraform/website/docs/r/container_cluster.html.markdown

@@ -582,7 +582,7 @@ for a list of types.
 
 * `minimum` - (Optional) Minimum amount of the resource in the cluster.
 
-* `maximum` - (Optional) Maximum amount of the resource in the cluster.
+* `maximum` - (Required) Maximum amount of the resource in the cluster.
 
 <a name="nested_auto_provisioning_defaults"></a>The `auto_provisioning_defaults` block supports: