Clean gallery about page post-1.0 (#26031)

examples/flutter_gallery/lib/gallery/about.dart

@@ -39,9 +39,9 @@ void showGalleryAboutDialog(BuildContext context) {
 
   showAboutDialog(
     context: context,
-    applicationVersion: 'April 2018 Preview',
+    applicationVersion: 'January 2019',
     applicationIcon: const FlutterLogo(),
-    applicationLegalese: '© 2017 The Chromium Authors',
+    applicationLegalese: '© 2019 The Chromium Authors',
     children: <Widget>[
       Padding(
         padding: const EdgeInsets.only(top: 24.0),
@@ -53,9 +53,9 @@ void showGalleryAboutDialog(BuildContext context) {
                 text: 'Flutter is an open-source project to help developers '
                       'build high-performance, high-fidelity, mobile apps for '
                       '${defaultTargetPlatform == TargetPlatform.iOS ? 'multiple platforms' : 'iOS and Android'} '
-                      'from a single codebase. This gallery is a preview of '
-                      "Flutter's many widgets, behaviors, animations, layouts, "
-                      'and more. Learn more about Flutter at '
+                      'from a single codebase. This design lab is a playground '
+                      "and showcase of Flutter's many widgets, behaviors, "
+                      'animations, layouts, and more. Learn more about Flutter at '
               ),
               _LinkTextSpan(
                 style: linkStyle,