fix(build): test example directories with unit and e2e tests (#11296)

modules/@angular/examples/_common/main-dynamic.ts

@@ -0,0 +1,11 @@
+/**
+ * @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 {platformBrowserDynamic} from '@angular/platform-browser-dynamic';
+import {AppModule} from './module';
+
+platformBrowserDynamic().bootstrapModule(AppModule);