Bugfix: prevent rare crash due to Actvity lifecycle events in AbstractTrackDeleteActivity.

src/main/java/de/dennisguse/opentracks/AbstractTrackDeleteActivity.java

@@ -96,11 +96,7 @@ public abstract class AbstractTrackDeleteActivity extends AbstractActivity imple
     protected abstract Track.Id getRecordingTrackId();
 
     @Override
-    public void connected() {
-        TrackDeleteService service = trackDeleteServiceConnection.getServiceIfBound();
-        if (service == null) {
-            return;
-        }
+    public void connected(TrackDeleteService service) {
         service.getDeletingStatusObservable().observe(AbstractTrackDeleteActivity.this, this::onTrackDeleteStatus);
     }
 }

src/main/java/de/dennisguse/opentracks/services/TrackDeleteServiceConnection.java

@@ -27,7 +27,7 @@ public class TrackDeleteServiceConnection implements ServiceConnection {
     @Override
     public void onServiceConnected(ComponentName name, IBinder service) {
         trackDeleteService = ((TrackDeleteService.Binder) service).getService();
-        listener.connected();
+        listener.connected(trackDeleteService);
     }
 
     @Override
@@ -60,11 +60,7 @@ public class TrackDeleteServiceConnection implements ServiceConnection {
         trackDeleteService = null;
     }
 
-    public TrackDeleteService getServiceIfBound() {
-        return trackDeleteService;
-    }
-
     public interface Listener {
-        void connected();
+        void connected(@NonNull TrackDeleteService service);
     }
 }