MC-38807: Preview Template button does not work in Queue Edit Page

Author: StasKozar

lib/web/mage/adminhtml/wysiwyg/tiny_mce/tinymce4Adapter.js

@@ -749,6 +749,13 @@ define([
          */
         addContentEditableAttributeBackToNonEditableNodes: function () {
             jQuery('.mceNonEditable', this.activeEditor().getDoc()).attr('contenteditable', false);
+        },
+
+        /**
+         * Calls the save method on all editor instances in the collection.
+         */
+        triggerSave: function () {
+            tinyMCE4.triggerSave();
         }
     };