Increase coverage of WaitSetTemplate (#1368)
Increase coverage of WaitSetTemplate (#1368)

* Increase coverage of WaitSetTemplate

Signed-off-by: Stephen Brawner <b1d598fdd857fd94ea5d1ed6be6151604c16b92a@gmail.com>

* PR fixup

Signed-off-by: Stephen Brawner <b1d598fdd857fd94ea5d1ed6be6151604c16b92a@gmail.com>
ros2/rclcpp,ros2/rclcpp