ENGCOM-7275: Fix issue with loading mask on Admin Checkout #27552

 - Merge Pull Request #27552 from lbajsarowicz/magento2:bugfix/loading-mask-admin-order-shipping-select
 - Merged commits:
   1. 96d56b2

Author: magento-engcom-team

app/code/Magento/Sales/Test/Mftf/ActionGroup/OrderSelectFlatRateShippingActionGroup.xml

@@ -14,7 +14,7 @@
         </annotations>
 
         <click selector="{{AdminOrderFormPaymentSection.header}}" stepKey="unfocus"/>
-        <waitForPageLoad stepKey="waitForJavascriptToFinish"/>
+        <waitForLoadingMaskToDisappear stepKey="waitForJavascriptToFinish"/>
         <click selector="{{AdminOrderFormPaymentSection.getShippingMethods}}" stepKey="clickShippingMethods"/>
         <waitForElementVisible selector="{{AdminOrderFormPaymentSection.flatRateOption}}" stepKey="waitForShippingOptions"/>
         <selectOption selector="{{AdminOrderFormPaymentSection.flatRateOption}}" userInput="flatrate_flatrate" stepKey="checkFlatRate"/>