Fix crash when speed dialog gets closed while handler is running (#8541)

### Description

Fix crash when speed dialog gets closed while handler is running. This
seems super hard to trigger, but apparently some of our beta testers
managed to do it.

### Checklist
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app/src/main/java/de/danoeh/antennapod/ui/screen/playback/VariableSpeedDialog.java

@@ -191,15 +191,13 @@ public class VariableSpeedDialog extends BottomSheetDialogFragment {
             });
             holder.chip.setOnClickListener(v -> {
                 UserPreferences.setPlaybackSpeed(speed);
-                new Handler(Looper.getMainLooper()).postDelayed(() -> {
-                    if (BuildConfig.USE_MEDIA3_PLAYBACK_SERVICE) {
-                        PlaybackController.bindToMedia3Service(getContext(),
-                                controller -> controller.setPlaybackSpeed(speed));
-                    } else if (controller != null) {
-                        controller.setPlaybackSpeed(speed);
-                    }
-                    dismiss();
-                }, 200);
+                if (BuildConfig.USE_MEDIA3_PLAYBACK_SERVICE) {
+                    PlaybackController.bindToMedia3Service(getContext(),
+                            controller -> controller.setPlaybackSpeed(speed));
+                } else if (controller != null) {
+                    controller.setPlaybackSpeed(speed);
+                }
+                new Handler(Looper.getMainLooper()).postDelayed(() -> dismiss(), 200);
             });
         }