Make renderer flush when setting pause-at-end more targeted.

We currently always reset everything if playingPeriod != readingPeriod.
However, this is only needed when the pausing is actually required, i.e.,
if the feature is enabled and we are in the last period of the window.

PiperOrigin-RevId: 328141242

library/core/src/main/java/com/google/android/exoplayer2/ExoPlayerImplInternal.java

@@ -733,11 +733,13 @@ import java.util.concurrent.atomic.AtomicBoolean;
   private void setPauseAtEndOfWindowInternal(boolean pauseAtEndOfWindow)
       throws ExoPlaybackException {
     this.pauseAtEndOfWindow = pauseAtEndOfWindow;
-    if (queue.getReadingPeriod() != queue.getPlayingPeriod()) {
+    resetPendingPauseAtEndOfPeriod();
+    if (pendingPauseAtEndOfPeriod && queue.getReadingPeriod() != queue.getPlayingPeriod()) {
+      // When pausing is required, we need to set the streams of the playing period final. If we
+      // already started reading the next period, we need to flush the renderers.
       seekToCurrentPosition(/* sendDiscontinuity= */ true);
+      handleLoadingMediaPeriodChanged(/* loadingTrackSelectionChanged= */ false);
     }
-    resetPendingPauseAtEndOfPeriod();
-    handleLoadingMediaPeriodChanged(/* loadingTrackSelectionChanged= */ false);
   }
 
   private void setOffloadSchedulingEnabledInternal(boolean offloadSchedulingEnabled) {