perf: flv设置自动清除缓存

@@ -15849,7 +15849,7 @@ class HandleDynamicEffect {
                     videoPlayConfig = {
                         ...videoPlayConfig,
                         muted: true,
-                        liveui: true, 
+                        liveui: true,
                         techOrder: ['html5', 'flvjs'],
                         flvjs: {
                             mediaDataSource: {
@@ -15857,6 +15857,8 @@ class HandleDynamicEffect {
                                 cors: true,
                                 hasAudio: false,
                                 withCredentials: false,
+                                autoCleanupSourceBuffer: true,
+                                autoCleanupMaxBackwardDuration: 60,
                             },
                             config: {
                                 headers: {