MC-3610: Remove use of legacy system within slide preview

 - fix selector

Author: cspruiell

app/code/Magento/PageBuilder/Test/Mftf/Section/PageBuilderSliderSection.xml

@@ -92,7 +92,7 @@
         <element name="collageLeft" type="button" selector="div[data-role='slide'] .pagebuilder-mobile-hidden[style*='40px calc(50% + 40px) 40px 40px'][style*='magento']"/>
         <element name="collageCentered" type="button" selector="div[data-role='slide'] .pagebuilder-mobile-hidden[style*='40px calc(25% + 40px)'][style*='magento']"/>
         <element name="collageRight" type="button" selector="div[data-role='slide'] .pagebuilder-mobile-hidden[style*='40px 40px 40px calc(50% + 40px)'][style*='magento']"/>
-        <element name="collageMargin" type="button" selector="div[data-role='slide'] pagebuilder-slide-wrapper[style*='margin: 1px 2px 3px 4px']"/>
+        <element name="collageMargin" type="button" selector="div[data-role='slide'] .pagebuilder-slide-wrapper[style*='margin: 1px 2px 3px 4px']"/>
         <element name="collageMinHeight" type="button" selector="div[data-role='slide'] .pagebuilder-mobile-hidden[style*='min-height: {{arg1}}px'][style*='magento']" parameterized="true"/>
         <element name="collageAlignment" type="button" selector="div[data-role='slide'] .pagebuilder-slide-wrapper[style*='text-align: center']"/>
         <element name="collageMobileWithoutMobileImage" type="button" selector="div[data-role='slide'] .pagebuilder-mobile-only[style*='padding: 40px;'][style*='magento']"/>