feat: [gdchardwaremanagement] Add OFFLINE state to Zone resources (#7513)

- [ ] Regenerate this pull request now.

A new `OFFLINE` state has been added to the `Zone.State` enum. This state indicates that the zone is temporarily not operational, for example, while undergoing maintenance or repair

PiperOrigin-RevId: 879057351

Source-Link: https://togithub.com/googleapis/googleapis/commit/40a49dc1a2305fecb768414c6837b65d3ea8b809

Source-Link: https://togithub.com/googleapis/googleapis-gen/commit/77daef772d6cb525e73509d99da77c54c86cb597
Copy-Tag: eyJwIjoicGFja2FnZXMvZ29vZ2xlLWNsb3VkLWdkY2hhcmR3YXJlbWFuYWdlbWVudC8uT3dsQm90LnlhbWwiLCJoIjoiNzdkYWVmNzcyZDZjYjUyNWU3MzUwOWQ5OWRhNzdjNTRjODZjYjU5NyJ9

Author: gcf-owl-bot[bot]

packages/google-cloud-gdchardwaremanagement/protos/google/cloud/gdchardwaremanagement/v1alpha/resources.proto

@@ -784,6 +784,9 @@ message Zone {
     // The Zone is ready for site turnup.
     READY_FOR_SITE_TURNUP = 6;
 
+    // The Zone is offline.
+    OFFLINE = 9;
+
     // The Zone failed in factory turnup checks.
     CUSTOMER_FACTORY_TURNUP_CHECKS_FAILED = 7;