fix(tier4_autoware_api_launch): add group tag (autowarefoundation#1235)

Signed-off-by: Xinyu Wang <xinyu.wang@tier4.jp>

Author: angry-crab

launch/tier4_autoware_api_launch/launch/autoware_api.launch.xml

@@ -16,7 +16,9 @@
 
   <!-- rosbridge -->
   <!-- TODO: respawn will work once https://github.com/ros2/launch/pull/569 is released. I'll delete this comment when it's done. -->
-  <include file="$(find-pkg-share rosbridge_server)/launch/rosbridge_websocket_launch.xml">
-    <arg name="respawn" value="$(var respawn_rosbridge)"/>
-  </include>
+  <group>
+    <include file="$(find-pkg-share rosbridge_server)/launch/rosbridge_websocket_launch.xml">
+      <arg name="respawn" value="$(var respawn_rosbridge)"/>
+    </include>
+  </group>
 </launch>