dart migrate add_to_app/fullscreen/flutter_module (#835)

add_to_app/fullscreen/flutter_module/lib/main.dart

@@ -58,7 +58,7 @@ class CounterModel extends ChangeNotifier {
 /// It offers two routes, one suitable for displaying as a full screen and
 /// another designed to be part of a larger UI.class MyApp extends StatelessWidget {
 class MyApp extends StatelessWidget {
-  const MyApp({Key key}) : super(key: key);
+  const MyApp({Key? key}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
@@ -75,7 +75,7 @@ class MyApp extends StatelessWidget {
 /// Wraps [Contents] in a Material [Scaffold] so it looks correct when displayed
 /// full-screen.
 class FullScreenView extends StatelessWidget {
-  const FullScreenView({Key key}) : super(key: key);
+  const FullScreenView({Key? key}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {
@@ -96,7 +96,7 @@ class FullScreenView extends StatelessWidget {
 class Contents extends StatelessWidget {
   final bool showExit;
 
-  const Contents({this.showExit = false, Key key}) : super(key: key);
+  const Contents({this.showExit = false, Key? key}) : super(key: key);
 
   @override
   Widget build(BuildContext context) {

add_to_app/fullscreen/flutter_module/pubspec.lock

@@ -63,7 +63,7 @@ packages:
       name: espresso
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "0.0.1+7"
+    version: "0.1.0+2"
   fake_async:
     dependency: transitive
     description:
@@ -160,7 +160,7 @@ packages:
       name: provider
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "4.3.3"
+    version: "5.0.0"
   sky_engine:
     dependency: transitive
     description: flutter
@@ -245,4 +245,4 @@ packages:
     version: "3.0.0"
 sdks:
   dart: ">=2.12.0 <3.0.0"
-  flutter: ">=1.16.0"
+  flutter: ">=1.20.0"

add_to_app/fullscreen/flutter_module/pubspec.yaml

@@ -4,20 +4,20 @@ description: An example Flutter module.
 version: 1.0.0+1
 
 environment:
-  sdk: ">=2.6.0-dev <3.0.0"
+  sdk: '>=2.12.0 <3.0.0'
 
 dependencies:
   flutter:
     sdk: flutter
-  provider: ^4.0.2
+  provider: ^5.0.0
 
 dev_dependencies:
   flutter_test:
     sdk: flutter
   flutter_driver:
     sdk: flutter
-  espresso: ^0.0.1+2
-  flutter_lints: ^1.0.0
+  espresso: ^0.1.0+2
+  flutter_lints: ^1.0.3
 
 flutter:
   uses-material-design: true