MC-5773: Add Missing P0-P1 MFTF Tests For PageBuilder On Schedule Update & Staging Dashboard

- add extra tab item to resolve dragAndDrop issue in modals

Author: anthoula

app/code/Magento/PageBuilder/Test/Mftf/Test/AdminPageBuilderTabGroupTests.xml

@@ -1363,6 +1363,9 @@
         <actionGroup ref="addChildContentTypeFromOptionMenu" stepKey="addChildContentType2">
             <argument name="contentType" value="PageBuilderTabsContentType"/>
         </actionGroup>
+        <actionGroup ref="addChildContentTypeFromOptionMenu" stepKey="addChildContentType3">
+            <argument name="contentType" value="PageBuilderTabsContentType"/>
+        </actionGroup>
         <see selector="{{TabOnStage.tabHeader('1')}}" userInput="{{PageBuilderTabName1Default.value}}" stepKey="seeTab1NameStage"/>
         <see selector="{{TabOnStage.tabHeader('2')}}" userInput="{{PageBuilderTabName2Default.value}}" stepKey="seeTab2NameStage"/>
         <actionGroup ref="moveTabItem" stepKey="moveTabItem">