[PlayQueue] Fix incorrect UI states of PlayQueue items

onNext(PlayQueueEvent) is called after onSubscribe() when opening the PlayQueueActivity. This is the intended behavior of the previosly used event broadcaster of the type BehaviorSubject<PlayQueueEvent>. The broadcaster's type was changed to PublishSubject<PlayQueueEvent> which does not emit the last event after onSubscribe().

Ref: #9669

Author: TobiGr

app/src/main/java/org/schabi/newpipe/player/playqueue/PlayQueue.java

@@ -23,7 +23,7 @@
 import io.reactivex.rxjava3.android.schedulers.AndroidSchedulers;
 import io.reactivex.rxjava3.core.BackpressureStrategy;
 import io.reactivex.rxjava3.core.Flowable;
-import io.reactivex.rxjava3.subjects.BehaviorSubject;
+import io.reactivex.rxjava3.subjects.PublishSubject;
 
 /**
  * PlayQueue is responsible for keeping track of a list of streams and the index of
@@ -46,7 +46,7 @@ public abstract class PlayQueue implements Serializable {
     private List<PlayQueueItem> backup;
     private List<PlayQueueItem> streams;
 
-    private transient BehaviorSubject<PlayQueueEvent> eventBroadcast;
+    private transient PublishSubject<PlayQueueEvent> eventBroadcast;
     private transient Flowable<PlayQueueEvent> broadcastReceiver;
     private transient boolean disposed = false;
 
@@ -71,7 +71,7 @@ public abstract class PlayQueue implements Serializable {
      * </p>
      */
     public void init() {
-        eventBroadcast = BehaviorSubject.create();
+        eventBroadcast = PublishSubject.create();
 
         broadcastReceiver = eventBroadcast.toFlowable(BackpressureStrategy.BUFFER)
                 .observeOn(AndroidSchedulers.mainThread())