public bool IsTrackAware {get;}

var trackAwareLayers = MapView.Active.Map.GetLayersAsFlattenedList()
                           .OfType<StreamLayer>().Where(sl => sl.IsTrackAware)?.ToList();

if (streamLayer.IsTrackAware)
{
  var trackField = streamLayer.TrackIdFieldName;
  //TODO use the field name
}

//Must be on QueuedTask
//Set Expiration Method and Max Expiration Count
if (streamLayer.GetExpirationMethod() != FeatureExpirationMethod.MaximumFeatureCount)
  streamLayer.SetExpirationMethod(FeatureExpirationMethod.MaximumFeatureCount);
streamLayer.SetExpirationMaxCount(15);
//FYI
if (streamLayer.IsTrackAware)
{
  //MaxCount is per track! otherwise for the entire layer
}