Add rviz argument to launch file to choose launching it or not

launch/realsense_test.launch

@@ -3,6 +3,7 @@
 
   <arg name="config_file" default="$(find iri_realsense_depth_bringup)/config/realsense_d435_default_config.yaml" />
   <arg name="camera_name" default="camera"/>
+  <arg name="rviz"        default="true"/>
 
   <param name="robot_description"
          command="$(find xacro)/xacro --inorder '$(find realsense2_description)/urdf/test_d435_camera.urdf.xacro'" />
@@ -15,6 +16,7 @@
   <node name="rviz"
         pkg="rviz"
         type="rviz"
+        if="$(arg rviz)"
         args="-d $(find iri_realsense_depth_bringup)/rviz/realsense_depth.rviz"/>
 
 </launch>