fix PiP issue

reproduction steps

- play a video
- swipe home to enter PiP
- minimize the video and then close it with the X
- swipe home (PiP will launch even though it shouldn't because nothing is playing)

Changelog: changed

app/src/main/java/com/futo/platformplayer/fragment/mainactivity/main/VideoDetailView.kt

@@ -1207,6 +1207,7 @@ class VideoDetailView : ConstraintLayout {
         _taskLoadVideo.cancel();
         handleStop();
         _didStop = true;
+        onShouldEnterPictureInPictureChanged.emit()
         Logger.i(TAG, "_didStop set to true");
 
         StatePlayer.instance.rotationLock = false;