Firebase Messaging请求权限触发空对象引用异常排查

我编写了一个用于请求Firebase Messaging权限的函数：

Future requestPermissionFCM() async {
  final FirebaseMessaging messaging = FirebaseMessaging.instance;

  final NotificationSettings settings = await messaging.requestPermission();
  if (settings.authorizationStatus == AuthorizationStatus.authorized) {
    print('User granted permision');
  } else if (settings.authorizationStatus == AuthorizationStatus.provisional) {
    print('User granted provisional permission');
  } else {
    print('user declined or has not accepted permission');
  }
}

在main.dart的initState方法中调用该函数时，final NotificationSettings settings = await messaging.requestPermission();这一行触发了未处理异常：

E/flutter (11771): [ERROR:flutter/runtime/dart_vm_initializer.cc(41)] Unhandled Exception: [firebase_messaging/unknown] Attempt to invoke virtual method 'java.lang.Object android.content.Context.getSystemService(java.lang.String)' on a null object reference
E/flutter (11771): #0      StandardMethodCodec.decodeEnvelope (package:flutter/src/services/message_codecs.dart:653:7)
E/flutter (11771): #1      MethodChannel._invokeMethod (package:flutter/src/services/platform_channel.dart:315:18)
E/flutter (11771): <asynchronous suspension>
E/flutter (11771): #2      MethodChannel.invokeMapMethod (package:flutter/src/services/platform_channel.dart:518:43)
E/flutter (11771): <asynchronous suspension>
E/flutter (11771): #3      MethodChannelFirebaseMessaging.requestPermission (package:firebase_messaging_platform_interface/src/method_channel/method_channel_messaging.dart:271:36)
E/flutter (11771): <asynchronous suspension>
E/flutter (11771): #4      requestPermissionFCM (package:dev/services/fcm_services.dart:30:41)
E/flutter (11771): <asynchronous suspension>

尽管出现该异常，应用并未崩溃，且消息功能（包括后台推送通知）仍正常工作，请问这是什么原因？

• 异常未引发崩溃：Dart的异步未处理异常默认不会直接导致应用崩溃，除非你配置了全局异常捕获并将其处理为崩溃逻辑。这个异常在异步函数中抛出且未被try/catch捕获，但Flutter异步运行时不会因此终止进程。
• 消息功能不受影响：Firebase Messaging的后台推送依赖设备与FCM服务器的连接，以及Android端FirebaseMessagingService这类后台组件的配置，这些不依赖前端主动请求通知权限。通知权限仅控制应用能否在前台显示通知横幅，不影响后台推送的送达。
• 空Context异常的根源：initState阶段Android侧的Context可能尚未初始化完成，此时调用requestPermission会触发getSystemService的空对象调用异常。但FCM核心推送逻辑不依赖这次权限请求的结果，所以功能依旧正常。

内容的提问来源于stack exchange，提问作者TonyWyomy