test: Remove useless StreamSubscription from e2e tests (#9674)

Author: lsaudon

packages/firebase_auth/firebase_auth_platform_interface/test/method_channel_tests/method_channel_firebase_auth_test.dart

@@ -1006,12 +1006,6 @@ void main() {
     });
 
     group('authStateChanges()', () {
-      StreamSubscription<UserPlatform?>? subscription;
-
-      tearDown(() {
-        subscription?.cancel();
-      });
-
       test('returns [Stream<UserPlatform>]', () async {
         // Checks that `authStateChanges` does not throw UnimplementedError
         expect(auth.authStateChanges(), isNotNull);
@@ -1051,12 +1045,6 @@ void main() {
     });
 
     group('idTokenChanges()', () {
-      StreamSubscription<UserPlatform?>? subscription;
-
-      tearDown(() {
-        subscription?.cancel();
-      });
-
       test('returns [Stream<UserPlatform>]', () async {
         // Checks that `idTokenChanges` does not throw UnimplementedError
         expect(auth.idTokenChanges(), isNotNull);
@@ -1097,12 +1085,6 @@ void main() {
     });
 
     group('userChanges()', () {
-      StreamSubscription<UserPlatform?>? subscription;
-
-      tearDown(() {
-        subscription?.cancel();
-      });
-
       test('returns [Stream<UserPlatform>]', () async {
         // Checks that `userChanges` does not throw UnimplementedError
         expect(auth.userChanges(), isNotNull);

packages/firebase_dynamic_links/firebase_dynamic_links_platform_interface/test/method_channel_tests/method_channel_firebase_dynamic_links_test.dart

@@ -2,8 +2,6 @@
 // Copyright 2021, the Chromium project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
-import 'dart:async';
-
 import 'package:firebase_core/firebase_core.dart';
 import 'package:firebase_dynamic_links_platform_interface/firebase_dynamic_links_platform_interface.dart';
 import 'package:firebase_dynamic_links_platform_interface/src/method_channel/method_channel_firebase_dynamic_links.dart';
@@ -293,12 +291,6 @@ void main() {
     });
 
     group('onLink()', () {
-      StreamSubscription<PendingDynamicLinkData?>? subscription;
-
-      tearDown(() {
-        subscription?.cancel();
-      });
-
       test('returns [Stream<PendingDynamicLinkData>]', () async {
         // Checks that `onLink` does not throw UnimplementedError
         expect(dynamicLinks.onLink, isNotNull);