Change GalleryScreen to StatelessWidget

Author: RusKryzhanovskiy

example/lib/screens/gallery_screen.dart

@@ -7,14 +7,9 @@ import 'package:flutter/cupertino.dart';
 import 'package:flutter/material.dart';
 import 'package:settings_ui/settings_ui.dart';
 
-class GalleryScreen extends StatefulWidget {
+class GalleryScreen extends StatelessWidget {
   const GalleryScreen({Key key}) : super(key: key);
 
-  @override
-  _GalleryScreenState createState() => _GalleryScreenState();
-}
-
-class _GalleryScreenState extends State<GalleryScreen> {
   @override
   Widget build(BuildContext context) {
     return Scaffold(