build error fixed

pubspec.yaml

@@ -87,7 +87,7 @@ flutter:
   # The following line ensures that the Material Icons font is
   # included with your application, so that you can use the icons in
   # the material Icons class.
-  uses-material-design: false
+  uses-material-design: true
 
   # To add assets to your application, add an assets section, like this:
   assets: