rviz_imu_plugin not properly initialized

[maracuya-robotics]

The visibility and scale of rviz_imu_plugin elements are not properly initialized when read from an rviz configuration file.

• Add an rviz_imu_plugin node to rviz and set its visibility to false
• Save the configuration and restart rviz

The acceleration arrow will be visible although the plugin node itself is set to invisible. Also axes are not scaled correctly. ImuDisplay::onInitialize() sets the visibility manually instead of calling the proper update methods (e.g. ImuDisplay::updateAxes()) which also sets the scale.

[mintar]

Thanks for the bug report! I don't have the time at the moment to work on this myself. However, if you could provide a pull request, I'd be happy to review and merge it!