Updated zh-CN translation

src/Ryujinx/Assets/locales.json

@@ -19697,7 +19697,7 @@
         "th_TH": "",
         "tr_TR": "",
         "uk_UA": "",
-        "zh_CN": "",
+        "zh_CN": "自动",
         "zh_TW": ""
       }
     },
@@ -19721,7 +19721,7 @@
         "th_TH": "",
         "tr_TR": "",
         "uk_UA": "",
-        "zh_CN": "",
+        "zh_CN": "使用Vulkan。\n在ARM Mac上，当玩在其下运行良好的游戏时，使用Metal后端。",
         "zh_TW": ""
       }
     },