Set tableSchema to chained extensions read context.

Author: alvinsee

.changes/next-release/bugfix-AWSSDKforJavav2-820a3eb.json

@@ -0,0 +1,6 @@
+{
+    "category": "AWS SDK for Java v2", 
+    "contributor": "alvinsee", 
+    "type": "bugfix", 
+    "description": "sets tableSchema field when provisioning the extension context in ChainExtension#afterRead"
+}

services-custom/dynamodb-enhanced/src/main/java/software/amazon/awssdk/enhanced/dynamodb/internal/extensions/ChainExtension.java

@@ -152,6 +152,7 @@ public ReadModification afterRead(DynamoDbExtensionContext.AfterRead context) {
                 DefaultDynamoDbExtensionContext.builder().items(itemToTransform)
                                                .operationContext(context.operationContext())
                                                .tableMetadata(context.tableMetadata())
+                                               .tableSchema(context.tableSchema())
                                                .build();
 
             ReadModification readModification = iterator.next().afterRead(afterRead);

services-custom/dynamodb-enhanced/src/test/java/software/amazon/awssdk/enhanced/dynamodb/extensions/ChainExtensionTest.java

@@ -276,6 +276,7 @@ private DefaultDynamoDbExtensionContext getExtensionContext(int i, OperationName
         DefaultDynamoDbExtensionContext.Builder context =
             DefaultDynamoDbExtensionContext.builder()
                                            .tableMetadata(FakeItem.getTableMetadata())
+                                           .tableSchema(FakeItem.getTableSchema())
                                            .operationContext(PRIMARY_CONTEXT)
                                            .items(fakeItems.get(i));
         if (operationName != null) {