feat: 拆分后台播放与AudioService在后台行为的设置

lib/pages/setting/play_setting.dart

@@ -140,20 +140,20 @@ class _PlaySettingState extends State<PlaySetting> {
           const SetSwitchItem(
             title: '后台播放',
             subTitle: '进入后台时继续播放',
-            setKey: SettingBoxKey.enableBackgroundPlay,
+            setKey: SettingBoxKey.continuePlayInBackground,
             defaultVal: true,
           ),
           if (Platform.isAndroid)
             SetSwitchItem(
                 title: '后台画中画',
-                subTitle: '进入后台时以小窗形式（PiP）播放，建议同时开启【后台播放】，避免没有暂停按钮',
+                subTitle: '进入后台时以小窗形式（PiP）播放',
                 setKey: SettingBoxKey.autoPiP,
                 defaultVal: false,
                 callFn: (val) {
                   if (val &&
                       !setting.get(SettingBoxKey.enableBackgroundPlay,
                           defaultValue: true)) {
-                    SmartDialog.showToast('建议开启后台播放');
+                    SmartDialog.showToast('建议开启后台音频服务');
                   }
                 }),
           if (Platform.isAndroid)
@@ -227,6 +227,12 @@ class _PlaySettingState extends State<PlaySetting> {
               }
             },
           ),
+          const SetSwitchItem(
+            title: '后台音频服务',
+            subTitle: '避免画中画没有播放暂停功能',
+            setKey: SettingBoxKey.enableBackgroundPlay,
+            defaultVal: true,
+          ),
         ],
       ),
     );