U4-9268 Hidden preview button reappears after 'save' or 'save and publish'.

src/Umbraco.Web/Editors/ContentController.cs

@@ -532,6 +532,7 @@ namespace Umbraco.Web.Editors
         /// <returns></returns>
         [FileUploadCleanupFilter]
         [ContentPostValidate]
+        [OutgoingEditorModelEvent]
         public ContentItemDisplay PostSave(
                 [ModelBinder(typeof(ContentItemBinder))]
                                 ContentItemSave contentItem)
@@ -847,6 +848,7 @@ namespace Umbraco.Web.Editors
         /// <param name="id"></param>
         /// <returns></returns>
         [EnsureUserPermissionForContent("id", 'U')]
+        [OutgoingEditorModelEvent]
         public ContentItemDisplay PostUnPublish(int id)
         {
             var foundContent = GetObjectFromRequest(() => Services.ContentService.GetById(id));

src/Umbraco.Web/Editors/MediaController.cs

@@ -464,6 +464,7 @@ namespace Umbraco.Web.Editors
         /// <returns></returns>
         [FileUploadCleanupFilter]
         [MediaPostValidate]
+        [OutgoingEditorModelEvent]
         public MediaItemDisplay PostSave(
             [ModelBinder(typeof(MediaItemBinder))]
                 MediaItemSave contentItem)

src/Umbraco.Web/Editors/MemberController.cs

@@ -256,6 +256,7 @@ namespace Umbraco.Web.Editors
         /// </summary>
         /// <returns></returns>        
         [FileUploadCleanupFilter]
+        [OutgoingEditorModelEvent]
         public MemberDisplay PostSave(
             [ModelBinder(typeof(MemberBinder))]
                 MemberSave contentItem)