Bug report

• Operating System: Ubuntu 20.04
• Installation type: Debian-based installation of ROS 2
• DDS implementation: any

Steps to reproduce issue

ros2 launch lifecycle lifecycle_demo.launch.py

Expected behavior

The script exits cleanly after the demo is done.

Actual behavior

The lifecycle_service_client runs through a script and exits, but the talker and listener are still active. It seems like the launch script could detect the exit of the lifecycle_service_client and exit the launch script.