Adjust internal build rollup to add proper @license annotation and SPDX License ID (#3723)

* Firestore Externs: @type -> @typedef

* Add @OverRide to Recaptcha Verify method in Auth Externs

* Add proper closure `@license` annotation to generated internal rollup boilerplate

* Google LLC + SPDX License ID

Author: richieforeman

packages/firebase/rollup-internal.config.js

@@ -1,6 +1,6 @@
 /**
  * @license
- * Copyright 2019 Google Inc.
+ * Copyright 2019 Google LLC
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -25,19 +25,9 @@ import baseBuilds from './rollup-main.config.js';
 import license from 'rollup-plugin-license';
 
 const firebaseLicense = license({
-  banner: `Copyright ${new Date().getFullYear()} Google Inc.
-
-  Licensed under the Apache License, Version 2.0 (the "License");
-  you may not use this file except in compliance with the License.
-  You may obtain a copy of the License at
-
-      http://www.apache.org/licenses/LICENSE-2.0
-
-  Unless required by applicable law or agreed to in writing, software
-  distributed under the License is distributed on an "AS IS" BASIS,
-  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-  See the License for the specific language governing permissions and
-  limitations under the License.`
+  banner: `@license
+  Copyright ${new Date().getFullYear()} Google LLC.
+  SPDX-License-Identifier: Apache-2.0`
 });
 
 const buildsWithLicense = baseBuilds.map(build => {