Update overrides.dart (#8083)

Author: sigurdm

app/lib/package/overrides.dart

@@ -44,6 +44,7 @@ final _reservedPackageNames = <String>[
   'ok_http', // https://github.com/dart-lang/http/tree/master/pkgs/ok_http
   'credilio_sbm', // for owner of package:crediliosbm
   'app_update',
+  'flutterkit',
 ].map(reducePackageName).toList();
 
 const redirectPackageUrls = <String, String>{