Reset screen order only when it is below a parent

Otherwise the default order from the action is lost when the screen is
instantiated.

issue9692
review302281002

src/screen.js

@@ -1184,9 +1184,11 @@
             this.views.map(function(view) {
                 view.reset();
             });
-            this.order = null;
             this.group = group;
             this.model = group.model;
+            if (this.group.parent) {
+                this.order = null;
+            }
             if (group && group.length) {
                 this.current_record = group[0];
             } else {