Update generated code (#1670)

update generated code

Author: async-aws-bot

src/DynamoDbClient.php

@@ -975,9 +975,9 @@ public function updateItem($input): UpdateItemOutput
      * - Create a new global secondary index on the table. After the index begins backfilling, you can use `UpdateTable` to
      *   perform other operations.
      *
-     * `UpdateTable` is an asynchronous operation; while it is executing, the table status changes from `ACTIVE` to
-     * `UPDATING`. While it is `UPDATING`, you cannot issue another `UpdateTable` request. When the table returns to the
-     * `ACTIVE` state, the `UpdateTable` operation is complete.
+     * `UpdateTable` is an asynchronous operation; while it's executing, the table status changes from `ACTIVE` to
+     * `UPDATING`. While it's `UPDATING`, you can't issue another `UpdateTable` request on the base table nor any replicas.
+     * When the table returns to the `ACTIVE` state, the `UpdateTable` operation is complete.
      *
      * [^1]: https://docs.aws.amazon.com/amazondynamodb/latest/developerguide/globaltables.V2.html
      *