update load param using node handle

config/obstacle_layer_params.yaml

@@ -0,0 +1,18 @@
+obstacle_layer:
+  track_unknown_space: true
+  transform_tolerance: 0.2
+  topic: "map"
+  sensor_frame: laser_frame
+  observation_persistence: 0.0
+  expected_update_rate: 0.0
+  data_type: PointCloud
+  min_obstacle_height: 0.0
+  max_obstacle_height: 2.0
+  inf_is_valid: false
+  clearing: false
+  marking: true
+  obstacle_range: 2.5
+  raytrace_range: 3.0
+  footprint_clearing_enabled: true
+  combination_method: 1
+