feat(tier4_perception_launch): enable to use multi camera on traffic …

…light recognition (autowarefoundation#1144)

change the way to declare camera num

Signed-off-by: MasatoSaeki <masato.saeki@tier4.jp>

autoware_launch/launch/components/tier4_perception_component.launch.xml

@@ -48,7 +48,7 @@
     <arg name="use_traffic_light_recognition" value="$(var use_traffic_light_recognition)"/>
     <arg name="traffic_light_recognition/enable_fine_detection" value="$(var traffic_light_recognition/enable_fine_detection)"/>
     <arg name="traffic_light_recognition/fusion_only" value="false"/>
-    <arg name="traffic_light_image_number" value="2"/>
+    <arg name="all_traffic_light_camera" value="[camera6, camera7]"/>
 
     <!-- object recognition parameters -->
     <arg