Fix Update method documentation to say "Update" instead of "Create" (Azure#53469)

* Initial plan

* Fix Update method documentation to say "Update" instead of "Create"

Co-authored-by: live1206 <[email protected]>

* Only override description for Create operations used as Update

Co-authored-by: live1206 <[email protected]>

---------

Co-authored-by: copilot-swe-agent[bot] <[email protected]>
Co-authored-by: live1206 <[email protected]>

Author: Copilot

eng/packages/http-client-csharp-mgmt/generator/Azure.Generator.Management/src/Providers/OperationMethodProviders/UpdateOperationMethodProvider.cs

@@ -3,15 +3,28 @@
 
 using Azure.Generator.Management.Models;
 using Microsoft.TypeSpec.Generator.Input;
+using System;
+using System.Runtime.CompilerServices;
 
 namespace Azure.Generator.Management.Providers.OperationMethodProviders
 {
-    internal class UpdateOperationMethodProvider(
-        ResourceClientProvider resource,
-        RequestPathPattern contextualPath,
-        RestClientInfo restClientInfo,
-        InputServiceMethod method,
-        bool isAsync) : ResourceOperationMethodProvider(resource, contextualPath, restClientInfo, method, isAsync, methodName: isAsync ? "UpdateAsync" : "Update")
+    internal class UpdateOperationMethodProvider : ResourceOperationMethodProvider
     {
+        public UpdateOperationMethodProvider(
+            ResourceClientProvider resource,
+            RequestPathPattern contextualPath,
+            RestClientInfo restClientInfo,
+            InputServiceMethod method,
+            bool isAsync,
+            ResourceOperationKind methodKind)
+            : base(resource, contextualPath, restClientInfo, method, isAsync, methodName: isAsync ? "UpdateAsync" : "Update", description: GetDescription(resource, methodKind))
+        {
+        }
+
+        private static FormattableString? GetDescription(ResourceClientProvider resource, ResourceOperationKind methodKind)
+        {
+            // Only override description if this is a Create operation being used as Update
+            return methodKind == ResourceOperationKind.Create ? FormattableStringFactory.Create("Update a {0}.", resource.ResourceName) : null;
+        }
     }
 }

eng/packages/http-client-csharp-mgmt/generator/Azure.Generator.Management/src/Providers/ResourceClientProvider.cs

@@ -437,10 +437,10 @@ protected override MethodProvider[] BuildMethods()
 
                 if (isUpdateOperation)
                 {
-                    var updateAsyncMethodProvider = new UpdateOperationMethodProvider(this, _contextualPath, restClientInfo, method, true);
+                    var updateAsyncMethodProvider = new UpdateOperationMethodProvider(this, _contextualPath, restClientInfo, method, true, methodKind);
                     operationMethods.Add(updateAsyncMethodProvider);
 
-                    updateMethodProvider = new UpdateOperationMethodProvider(this, _contextualPath, restClientInfo, method, false);
+                    updateMethodProvider = new UpdateOperationMethodProvider(this, _contextualPath, restClientInfo, method, false, methodKind);
                     operationMethods.Add(updateMethodProvider);
                 }
                 else