.NET v4: Add missing snippet for DynamoDB scenario (#7714)

Author: rlhagerm

.doc_gen/metadata/dynamodb_metadata.yaml

@@ -1878,6 +1878,9 @@ dynamodb_Scenario_GettingStartedMovies:
             - description:
               snippet_tags:
                 - DynamoDB.dotnetv4.DynamoDB_Basics_Scenario
+            - description: Use the injected client for table operations.
+              snippet_tags:
+                - DynamoDB.dotnetv4.dynamodb-basics.DynamoDbWrapper
             - description: Creates a table to contain movie data.
               snippet_tags:
                 - DynamoDB.dotnetv4.dynamodb-basics.CreateTable

dotnetv4/DynamoDB/Actions/DynamoDbWrapper.cs

@@ -1,6 +1,7 @@
 // Copyright Amazon.com, Inc. or its affiliates. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
 
+// snippet-start:[DynamoDB.dotnetv4.dynamodb-basics.DynamoDbWrapper]
 using System.Text.Json;
 using Amazon.DynamoDBv2;
 using Amazon.DynamoDBv2.DataModel;
@@ -24,6 +25,8 @@ public DynamoDbWrapper(IAmazonDynamoDB amazonDynamoDB)
     {
         _amazonDynamoDB = amazonDynamoDB;
     }
+    // snippet-end:[DynamoDB.dotnetv4.dynamodb-basics.DynamoDbWrapper]
+
     // snippet-start:[DynamoDB.dotnetv4.dynamodb-basics.CreateTable]
 
     /// <summary>