如何使用flutter android在firebase firestore中保存图片？

dependencies:
  flutter:
    sdk: flutter
  firebase_core: ^1.0.0
  cloud_firestore: ^2.0.0
  firebase_storage: ^8.0.0

import 'package:firebase_core/firebase_core.dart';
import 'package:cloud_firestore/cloud_firestore.dart';
import 'package:firebase_storage/firebase_storage.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp();
  runApp(MyApp());
}

final CollectionReference imagesCollection = FirebaseFirestore.instance.collection('images');

Future<void> saveImageToFirestore(String imageUrl) {
  return imagesCollection.doc().set({
    'imageUrl': imageUrl,
  });
}

final Reference storageReference = FirebaseStorage.instance.ref().child('images');

Future<String> uploadImageToFirebase(File imageFile) async {
  TaskSnapshot snapshot = await storageReference.putFile(imageFile);
  String imageUrl = await snapshot.ref.getDownloadURL();
  return imageUrl;
}

File imageFile = File('path/to/image.jpg');
String imageUrl = await uploadImageToFirebase(imageFile);
await saveImageToFirestore(imageUrl);