MC-23059: Template strict mode is not set for unsaved template previews

Author: nathanjosiah

app/code/Magento/Newsletter/Test/Mftf/ActionGroup/AdminNewsletterTemplateActionGroup.xml

@@ -36,6 +36,7 @@
         <switchToNextTab stepKey="switchToPreviewTab"/>
         <waitForElementVisible selector="{{BasicFieldNewsletterSection.previewIframe}}" stepKey="waitForIframeVisible"/>
         <executeJS function="document.getElementById('preview_iframe').sandbox.add('allow-scripts')" stepKey="addSandboxValue"/>
+        <wait time="10" stepKey="waitForSandbox"/>
         <switchToIFrame userInput="preview_iframe" stepKey="switchToIframe"/>
         <waitForPageLoad stepKey="waitForPreviewIframeLoaded"/>
     </actionGroup>
@@ -44,6 +45,6 @@
         <arguments>
             <argument name="Newsletter" defaultValue="BasicFieldNewsletterSection"/>
         </arguments>
-        <waitForText userInput="{{Newsletter.expectedTemplate}}" stepKey="checkTemplateContainsText"/>
+        <waitForText userInput="{{Newsletter.expectedTemplate}}" stepKey="checkTemplateContainsText" time="30"/>
     </actionGroup>
 </actionGroups>