Add missing copyright

Author: lbajsarowicz

app/code/Magento/Customer/Test/Mftf/ActionGroup/AdminGridCustomerGroupEditByCodeActionGroup.xml

@@ -1,4 +1,9 @@
 <?xml version="1.0" encoding="UTF-8"?>
+<!--
+/**
+ * Copyright © Magento, Inc. All rights reserved.
+ * See COPYING.txt for license details.
+-->
 
 <actionGroups xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
               xsi:noNamespaceSchemaLocation="urn:magento:mftf:Test/etc/actionGroupSchema.xsd">