Sony completed "Wait For an Acknowledgment". (ros2#2269)

Signed-off-by: Tomoya.Fujita <[email protected]>

Author: fujitatomoya

source/Roadmap.rst

@@ -126,7 +126,7 @@ If you'd like to take on one of these tasks, please :doc:`get in touch with us <
    * - Wait for an acknowledgment from a reliable publisher in rclcpp and rclpy
      - Small
      - Sony
-     - 4th quarter 2021
+     - Complete
 
 
 Additional project-specific roadmaps can be found in the links below: