MC-4093: Couldn't hide buttons group when appearance is set as Stacked

- Add missing hide / show class, for if we decide to hide buttons

Author: davemacaulay

app/code/Magento/PageBuilder/view/adminhtml/web/template/content-type/buttons/stacked/preview.html

@@ -8,6 +8,6 @@
 <div class="pagebuilder-content-type pagebuilder-entity pagebuilder-entity-preview pagebuilder-no-blur pagebuilder-live-edit pagebuilder-buttons" event="{ mouseover: onMouseOver, mouseout: onMouseOut }, mouseoverBubble: false">
     <render args="getOptions().template" />
     <div class="element-children buttons-container" each="parent.getChildren()" attr="Object.assign({}, data.main.attributes(), { id: parent.id + '-children' })" ko-style="data.main.style" css="data.main.css" data-bind="sortableChildren: getSortableOptions('height', 'pointer')">
-        <div class="pagebuilder-content-type-wrapper" template="{ name: preview.previewTemplate, data: preview, afterRender: function () { preview.dispatchAfterRenderEvent.apply(preview, arguments); } }" attr="{ id: id }"></div>
+        <div class="pagebuilder-content-type-wrapper" template="{ name: preview.previewTemplate, data: preview, afterRender: function () { preview.dispatchAfterRenderEvent.apply(preview, arguments); } }" attr="{ id: id }" css="{'pagebuilder-content-type-hidden': !preview.display()}"></div>
     </div>
 </div>