fix(router): fix lazy loading of aux routes (#23459)

Fixes #10981

PR Close #23459

packages/router/src/components/empty_outlet.ts

@@ -0,0 +1,22 @@
+/**
+ * @license
+ * Copyright Google Inc. All Rights Reserved.
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+import {Component} from '@angular/core';
+
+/**
+ * This component is used internally within the router to be a placeholder when an empty
+ * router-outlet is needed. For example, with a config such as:
+ *
+ * `{path: 'parent', outlet: 'nav', children: [...]}`
+ *
+ * In order to render, there needs to be a component on this config, which will default
+ * to this `EmptyOutletComponent`.
+ */
+@Component({template: `<router-outlet></router-outlet>`})
+export class EmptyOutletComponent {
+}