Provide defaults for ParameterValue fields (#18)
Provide defaults for ParameterValue fields (#18)

* Provide defaults for ParameterValue fields

Even though only one field for a particular parameter is intended to be used, to prevent serialisation of uninitialised fields we put defaults for all of them

* Remove unnecessary default for bytes_value

* False->false to match design spec

ros2/rcl_interfaces,ros2/rcl_interfaces