(fix): tag VM as Azure Kubernetes Service

packer/aztack.json

@@ -28,7 +28,7 @@
       "image_sku": "16.04-LTS",
       "image_version": "latest",
       "azure_tags": {
-        "dept": "Azure Container Service"
+        "dept": "Azure Kubernetes Service"
       },
 
       "location": "{{user `location`}}",