MAGETWO-96010: [2.2] Restricted admin still able to send order comment email modifying POST request

- Unit test fix

Author: SeruyV

app/code/Magento/Sales/Test/Unit/Controller/Adminhtml/Order/AddCommentTest.php

@@ -3,11 +3,12 @@
  * Copyright © Magento, Inc. All rights reserved.
  * See COPYING.txt for license details.
  */
+declare(strict_types=1);
+
 namespace Magento\Sales\Test\Unit\Controller\Adminhtml\Order;
 
 /**
  * Test for AddComment.
- *
  */
 class AddCommentTest extends \PHPUnit\Framework\TestCase
 {