import packages, initialize firebase asynchronously and make Google map run on Android platform surface

main.dart

import 'package:firebase_core/firebase_core.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:flutter_screenutil/flutter_screenutil.dart';
import 'package:google_maps_flutter/google_maps_flutter.dart';
import 'package:oshinowoa_firebase_gis/screens/home_screen.dart';

void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  await Firebase.initializeApp();
  if (defaultTargetPlatform == TargetPlatform.android) {
    AndroidGoogleMapsFlutter.useAndroidViewSurface = true;
  }
  runApp(const GisApp());
}

class GisApp extends StatelessWidget {
  const GisApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return ScreenUtilInit(
      designSize: const Size(360, 690),
      builder: () => MaterialApp(
        debugShowCheckedModeBanner: false,
        title: 'Gis App',
        theme: ThemeData(
          visualDensity: VisualDensity.adaptivePlatformDensity,
        ),
        home: const HomeScreen(),
      ),
    );
  }
}