[google_sign_in_web] Ignore analyzer checks in generated files. (#3622)

These checks are currently breaking the engine/framework rolls.

Author: ditman

packages/google_sign_in/google_sign_in_web/lib/src/generated/gapi.dart

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// ignore_for_file: public_member_api_docs, unused_element
+
 @JS()
 library gapi;
 

packages/google_sign_in/google_sign_in_web/lib/src/generated/gapiauth2.dart

@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+// ignore_for_file: public_member_api_docs, unused_element
+
 @JS()
 library gapiauth2;