fix(radar_tracks_noise_filter): delete default param in src (autowarefoundation#6310)

Signed-off-by: scepter914 <scepter914@gmail.com>

Author: scepter914

sensing/radar_tracks_noise_filter/src/radar_tracks_noise_filter_node/radar_tracks_noise_filter_node.cpp

@@ -52,7 +52,7 @@ RadarTrackCrossingNoiseFilterNode::RadarTrackCrossingNoiseFilterNode(
     std::bind(&RadarTrackCrossingNoiseFilterNode::onSetParam, this, std::placeholders::_1));
 
   // Node Parameter
-  node_param_.velocity_y_threshold = declare_parameter<double>("velocity_y_threshold", 7.0);
+  node_param_.velocity_y_threshold = declare_parameter<double>("velocity_y_threshold");
 
   // Subscriber
   sub_tracks_ = create_subscription<RadarTracks>(