refactor: add license header to JS files & format files (#12081)

modules/@angular/platform-browser-dynamic/rollup-testing.config.js

@@ -1,6 +1,15 @@
+/**
+ * @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
+ */
+
 export default {
   entry: '../../../dist/packages-dist/platform-browser-dynamic/testing/index.js',
-  dest: '../../../dist/packages-dist/platform-browser-dynamic/bundles/platform-browser-dynamic-testing.umd.js',
+  dest:
+      '../../../dist/packages-dist/platform-browser-dynamic/bundles/platform-browser-dynamic-testing.umd.js',
   format: 'umd',
   moduleName: 'ng.platformBrowserDynamic.testing',
   globals: {
@@ -13,4 +22,4 @@ export default {
     '@angular/platform-browser/testing': 'ng.platformBrowser.testing',
     '@angular/platform-browser-dynamic': 'ng.platformBrowserDynamic'
   }
-}
+};