magento-test/app/code/Magento/Sales/Test/Mftf/ActionGroup/AdminChangeCustomerOptionFileActionGroup.xml

<?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">
    <actionGroup name="AdminChangeCustomerOptionFileActionGroup">
        <annotations>
            <description>Change custom option file on admin order page.</description>
        </annotations>
        <arguments>
            <argument name="file" type="string" defaultValue="{{TestImageNew.file}}"/>
        </arguments>

        <click selector="{{AdminOrderFormItemsSection.configure}}" stepKey="clickConfigure"/>
        <waitForPageLoad stepKey="waitForAjaxLoad"/>
        <waitForElementVisible selector="{{AdminOrderFormCustomOptionsSection.linkChange}}" stepKey="waitForLinkChange"/>
        <click selector="{{AdminOrderFormCustomOptionsSection.linkChange}}" stepKey="clickLinkChange"/>
        <waitForPageLoad stepKey="waitForChangeLoad"/>
        <waitForElementVisible selector="{{AdminOrderFormCustomOptionsSection.file}}" stepKey="waitForAttachImage"/>
        <attachFile selector="{{AdminOrderFormCustomOptionsSection.file}}" userInput="{{file}}" stepKey="changeAttachImage"/>
        <waitForPageLoad stepKey="waitForImageUploaded"/>
        <click selector="{{AdminOrderFormCustomOptionsSection.buttonOk}}" stepKey="clickButtonOK"/>
        <waitForPageLoad stepKey="waitForCustomOptionApplied"/>
        <waitForElementNotVisible selector="{{AdminOrderFormCustomOptionsSection.buttonOk}}" stepKey="waitForOkButtonGone"/>
    </actionGroup>
</actionGroups>