title: Only blank white screen is displayed when i run my flutter app
body: <p>iam using flutter upgraded version and the app builds fine before writing the code to get data from firebase but after this when i run my app only white scree appears on my mobile
  <strong>here is my main.dart code</strong></p>
  <pre><code>import 'package:flutter/material.dart';
  import 'package:mints/home.dart';
  import 'dart:async';
  import 'package:firebase_core/firebase_core.dart';
  
  void main() async{
    WidgetsFlutterBinding.ensureInitialized();
    await Firebase.initializeApp();
    runApp(MaterialApp(
      home:Home(),
    ));
  }
  </code></pre>
  <p><strong>home.dart code</strong></p>
  <pre><code>import 'package:flutter/material.dart';
  import 'package:cloud_firestore/cloud_firestore.dart';
  import 'dart:async';
  import 'package:flutter_swiper/flutter_swiper.dart';
  import 'package:firebase_core/firebase_core.dart';
  
  
  
  class Home extends StatefulWidget {
    @override
    _HomeState createState() =&gt; new _HomeState();
  }
  
  class _HomeState extends State&lt;Home&gt; {
  
    StreamSubscription&lt;QuerySnapshot&gt;subscription;
  
    List&lt;DocumentSnapshot&gt;snapshot;
  
    CollectionReference collectionReference = FirebaseFirestore.instance.collection(&quot;mints&quot;);
  
    @override
    void initState() {
      subscription = collectionReference.snapshots().listen((datasnap) { 
        setState(() {
          snapshot = datasnap.docs;
        });
      });
      super.initState();
       
    }
    Widget build (BuildContext context) {
      return new Scaffold(
        appBar: AppBar(
          title: Text(&quot;Mints&quot;),
          backgroundColor: Colors.teal[200],
        ),
  
        drawer: Drawer(
          child:Container(
              color: Colors.teal[200],
              child: ListView(
              children:&lt;Widget&gt;[
                UserAccountsDrawerHeader(
                  accountName: Text(&quot;CONTACT US AT&quot;), 
                  accountEmail: Text(&quot;mintslpu@gmail.com&quot;),
                  decoration: BoxDecoration(color: Colors.black),
                  )
              ]
            ),
          ),
        ),
  
        body: Padding(
          padding: EdgeInsets.only(top: 30.0),
          child: Swiper(
            itemBuilder: (BuildContext context, int index) {
              return InkWell(
                  child: Stack(
                    children: &lt;Widget&gt;[
                      Padding(
                        padding: EdgeInsets.all(10.0),
                        child: ClipRRect(
                          borderRadius: BorderRadius.only(
                            topLeft: Radius.circular(35.0),
                            topRight: Radius.circular(35.0),
                          ),
                          child: Image.network(
                            snapshot[index].data()['image'] ,
                            fit: BoxFit.cover,
                            height: 400.0,
                          ),
                        ),
                      ),
                      Padding(
                        padding: EdgeInsets.fromLTRB(0.0, 350.0, 0.0, 0.0),
                        child: Container(
                          height: 200.0,
                          width: 400.0,
                          child: Material(
                            borderRadius: BorderRadius.circular(35.0),
                            elevation: 10.0,
                            child: Column(
                              children:&lt;Widget&gt;[
                                Padding(
                                  padding: EdgeInsets.fromLTRB(20.0, 20.0, 10.0, 20.0),
                                  child: Text(
                                    snapshot[index].data()['title'] ,
                                    style: TextStyle(
                                      fontSize: 25.0,
                                      fontWeight: FontWeight.bold,
                                    ),
                                  ),
                                )
                              ]
                            ),
                          ),
                        ),
                      )
                    ],
                  ),
              );
            },
            itemCount: snapshot == null ? 0 : snapshot.length, autoplay: true,viewportFraction: 0.8,
                  scale: 0.9,
          ),
        )
      );
    }
  }
  </code></pre>
  <p><strong>when i run the app and after it it is built this is being displayed in the vs code terminal</strong></p>
  <pre><code>E/flutter (32259): [ERROR:flutter/lib/ui/ui_dart_state.cc(177)] Unhandled Exception: [core/not-initialized] Firebase has not been correctly initialized. Have you added the &quot;google-services.json&quot; file to the project?
  E/flutter (32259):     
  E/flutter (32259):     View the Android Installation documentation for more information: https://firebaseextended.github.io/flutterfire/docs/installation/android
  E/flutter (32259):
  E/flutter (32259): #0      MethodChannelFirebase.initializeApp (package:firebase_core_platform_interface/src/method_channel/method_channel_firebase.dart:86:9)
  E/flutter (32259): &lt;asynchronous suspension&gt;
  E/flutter (32259): #1      Firebase.initializeApp (package:firebase_core/src/firebase.dart:43:25)
  E/flutter (32259): #2      main (package:mints/main.dart:8:18)
  E/flutter (32259): #3      _runMainZoned.&lt;anonymous closure&gt;.&lt;anonymous closure&gt; (dart:ui/hooks.dart:231:25)
  E/flutter (32259): #4      _rootRun (dart:async/zone.dart:1190:13)
  E/flutter (32259): #5      _CustomZone.run (dart:async/zone.dart:1093:19)
  E/flutter (32259): #6      _runZoned (dart:async/zone.dart:1630:10)
  E/flutter (32259): #7      runZonedGuarded (dart:async/zone.dart:1618:12)
  E/flutter (32259): #8      _runMainZoned.&lt;anonymous closure&gt; (dart:ui/hooks.dart:223:5)
  E/flutter (32259): #9      _startIsolate.&lt;anonymous closure&gt; (dart:isolate-patch/isolate_patch.dart:301:19)
  E/flutter (32259): #10     _RawReceivePortImpl._handleMessage (dart:isolate-patch/isolate_patch.dart:168:12)
  E/flutter (32259):
  </code></pre>
  <p><em>Thanks in Advance</em></p>