ROS2: Parameter description hotfix

[klintan]

Couldn't compile in dashing because declare_parameter needed 3 arguments, haven't seen that before, but it seems the parameter_interface does not have a default value for ParameterDescription.

edit: fails because it runs on crystal, some of these changes are dashing-specific.

[klintan]

Running tests locally everything is fine except for the parameter: name = 'diagnostic_updater.period'
even though it's not a topic it complains it's not a valid topic name. Should we change the parameter name to diagnostics_updated_period ?

[Karsten1987]

The default value got backported to dashing in here ros2/rclcpp#794

Are you sure you are working with the latest dashing release? You might have to upgrade your system (sudo apt-get upgrade) or try working with the latest testing release repos: https://wiki.ros.org/TestingRepository

Looking at the PR introducing the parameter, the build worked successfully on all platforms with dashing: #112

I am going to close this as I believe using the latest dashing debs might solve your problem. Feel free to re-open this ticket if your problems persists.