feat(player): 倍速改为底部弹窗选择

lib/l10n/app_localizations_en.dart

@@ -139,6 +139,9 @@ class AppLocalizationsEn extends AppLocalizations {
   @override
   String get exitClearScreen => 'Exit clear screen';
 
+  @override
+  String get playbackSpeed => 'Playback speed';
+
   @override
   String minutesAgo(int count) {
     return '$count min ago';