flutter: Modify restart dialog button text

src/ui/flutter_app/lib/l10n/intl_en.arb

@@ -112,6 +112,10 @@
   "@restartGame": {
     "description": "Restart Game?"
   },
+  "restart": "Restart",
+  "@restart": {
+    "description": "Restart"
+  },
   "gameStarted": "Game started, please place",
   "@gameStarted": {
     "description": "Game started, please place"

src/ui/flutter_app/lib/l10n/intl_zh.arb

@@ -28,6 +28,7 @@
   "thinking": "对方思考中...",
   "newGame": "新局",
   "restartGame": "重新开局？",
+  "restart": "重开局",
   "gameStarted": "游戏开始 请落子",
   "analyzing": "正在分析局面...",
   "error": "错误",

src/ui/flutter_app/lib/widgets/game_page.dart

@@ -275,7 +275,7 @@ class _GamePageState extends State<GamePage> with RouteAware {
           content:
               SingleChildScrollView(child: Text(S.of(context).restartGame)),
           actions: <Widget>[
-            TextButton(child: Text(S.of(context).ok), onPressed: confirm),
+            TextButton(child: Text(S.of(context).restart), onPressed: confirm),
             TextButton(child: Text(S.of(context).cancel), onPressed: cancel),
           ],
         );