fix(player): 收敛播放入口缓冲提示

test/playback/seek_progress_bar_test.dart

@@ -17,21 +17,26 @@ void main() {
     expect(seekPositionForFraction(1, duration), lessThan(duration));
   });
 
-  testWidgets('should_show_loading_track_when_controller_is_missing', (
+  testWidgets('should_show_inactive_track_when_video_is_not_initialized', (
     tester,
   ) async {
+    final video = ValueNotifier<VideoPlayerValue>(
+      const VideoPlayerValue.uninitialized(),
+    );
+    addTearDown(video.dispose);
     await tester.pumpWidget(
       MaterialApp(
         home: Scaffold(
           body: SeekProgressBar(
-            valueListenable: null,
+            valueListenable: video,
             semanticsLabel: 'Seek video',
           ),
         ),
       ),
     );
 
-    expect(find.byKey(const Key('progress-loading')), findsOneWidget);
+    expect(find.byKey(const Key('progress-loading')), findsNothing);
+    expect(find.byKey(const Key('progress-inactive')), findsOneWidget);
     expect(find.byType(Slider), findsNothing);
   });