Add an example for Config Sync auto-upgrades into google_gkehub_featu…

…re_membership resource doc (GoogleCloudPlatform#11684)

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

@@ -8,7 +8,10 @@ description: |-
 
 Contains information about a GKEHub Feature Memberships. Feature Memberships configure GKEHub Features that apply to specific memberships rather than the project as a whole. The google_gke_hub is the Fleet API.
 
-## Example Usage - Config Management
+## Example Usage - Config Management with Config Sync auto-upgrades and without Git/OCI
+
+With [Config Sync auto-upgrades](https://cloud.devsite.corp.google.com/kubernetes-engine/enterprise/config-sync/docs/how-to/upgrade-config-sync#auto-upgrade-config), Google assumes responsibility for automatically upgrading Config Sync versions
+and overseeing the lifecycle of its components.
 
 ```hcl
 resource "google_container_cluster" "cluster" {
@@ -40,17 +43,20 @@ resource "google_gke_hub_feature_membership" "feature_member" {
   feature = google_gke_hub_feature.feature.name
   membership = google_gke_hub_membership.membership.membership_id
   configmanagement {
-    version = "1.19.0"
+    # Don't use the `version` field with Config Sync auto-upgrades.
+    # To disable Config Sync auto-upgrades, you need to set the field `management` to
+    # `MANAGEMENT_MANUAL` if it has been set previously. Removing the field does not work.
+    management= "MANAGEMENT_AUTOMATIC"
     config_sync {
+      # The field `enabled` was introduced in Terraform version 5.41.0, and
+      # needs to be set to `true` explicitly to install Config Sync.
       enabled = true
-      git {
-        sync_repo = "https://github.com/hashicorp/terraform"
-      }
     }
   }
 }
 ```
-## Example Usage - Config Management with OCI
+
+## Example Usage - Config Management with Git
 
 ```hcl
 resource "google_container_cluster" "cluster" {
@@ -85,31 +91,15 @@ resource "google_gke_hub_feature_membership" "feature_member" {
     version = "1.19.0"
     config_sync {
       enabled = true
-      oci {
-        sync_repo = "us-central1-docker.pkg.dev/sample-project/config-repo/config-sync-gke:latest"
-        policy_dir = "config-connector"
-        sync_wait_secs = "20"
-        secret_type = "gcpserviceaccount"
-        gcp_service_account_email = "[email protected]"
+      git {
+        sync_repo = "https://github.com/hashicorp/terraform"
       }
     }
   }
 }
 ```
 
-## Example Usage - Multi Cluster Service Discovery
-
-```hcl
-resource "google_gke_hub_feature" "feature" {
-  name = "multiclusterservicediscovery"
-  location = "global"
-  labels = {
-    foo = "bar"
-  }
-}
-```
-
-## Example Usage - Service Mesh
+## Example Usage - Config Management with OCI
 
 ```hcl
 resource "google_container_cluster" "cluster" {
@@ -128,16 +118,30 @@ resource "google_gke_hub_membership" "membership" {
 }
 
 resource "google_gke_hub_feature" "feature" {
-  name = "servicemesh"
+  name = "configmanagement"
   location = "global"
+
+  labels = {
+    foo = "bar"
+  }
 }
 
 resource "google_gke_hub_feature_membership" "feature_member" {
   location = "global"
   feature = google_gke_hub_feature.feature.name
   membership = google_gke_hub_membership.membership.membership_id
-  mesh {
-    management = "MANAGEMENT_AUTOMATIC"
+  configmanagement {
+    version = "1.19.0"
+    config_sync {
+      enabled = true
+      oci {
+        sync_repo = "us-central1-docker.pkg.dev/sample-project/config-repo/config-sync-gke:latest"
+        policy_dir = "config-connector"
+        sync_wait_secs = "20"
+        secret_type = "gcpserviceaccount"
+        gcp_service_account_email = "[email protected]"
+      }
+    }
   }
 }
 ```
@@ -187,6 +191,51 @@ resource "google_gke_hub_feature_membership" "feature_member" {
 }
 ```
 
+## Example Usage - Multi Cluster Service Discovery
+
+```hcl
+resource "google_gke_hub_feature" "feature" {
+  name = "multiclusterservicediscovery"
+  location = "global"
+  labels = {
+    foo = "bar"
+  }
+}
+```
+
+## Example Usage - Service Mesh
+
+```hcl
+resource "google_container_cluster" "cluster" {
+  name               = "my-cluster"
+  location           = "us-central1-a"
+  initial_node_count = 1
+}
+
+resource "google_gke_hub_membership" "membership" {
+  membership_id = "my-membership"
+  endpoint {
+    gke_cluster {
+      resource_link = "//container.googleapis.com/${google_container_cluster.cluster.id}"
+    }
+  }
+}
+
+resource "google_gke_hub_feature" "feature" {
+  name = "servicemesh"
+  location = "global"
+}
+
+resource "google_gke_hub_feature_membership" "feature_member" {
+  location = "global"
+  feature = google_gke_hub_feature.feature.name
+  membership = google_gke_hub_membership.membership.membership_id
+  mesh {
+    management = "MANAGEMENT_AUTOMATIC"
+  }
+}
+```
+
 ## Example Usage - Policy Controller with minimal configuration
 
 ```hcl