[AdmittanceController] Dupplication of objects in `on_init` and `on_configure` methods

[destogl]

This is duplicated code in on_init and in on_configure methods, and it should be removed from on_configure. The objects should have lifetime of the controller, but they should be resetted. Maybe admittance_rule_ should be created here and not in on_init. The reason for that is resetting parameters completely when reconfiguring controller.

https://github.com/ros-controls/ros2_controllers/blob/f4788c594026bc3ecf0d944e1fa39f3f2d40673b/admittance_controller/src/admittance_controller.cpp#L150-L160

[Maverobot]

The mentioned redundancy does not seem to exist any more. Can this issue be closed? @destogl

[bailaC]

@destogl we can close this issue.