valkyrie_ros_api.launch parameter issues

[tkoolen]

There are two parameter issues with valkyrie_ros_api.launch:

1. as discussed with @dljsjr, /use_sim_time is hardcoded to true, which can cause hard-to-debug time issues (t not ticking in RemoteValkyrieVisualizer, causing calibration to never finish, boxStep.py issues because rate.sleep() sleeps forever).
2. valkyrie_A.urdf is hardcoded.

For 1, should /use_sim_time just always be set to false? It looks like this launch file is never meant to be run in simulation.

For 2, what is the right place to get the appropriate URDF file?

[dljsjr]

The URDF model shouldn't really matter as long as it's not the sim model, as the physical properties are the same between A/B/C/D; the only differences are the custom tags that encode the TurboDriver information which doesn't impact the Robot State Publisher.. URDF's assume a working installation of Val Description from NASA.

The Sim Time parameter should probably default to false and we should either provide two separate launch files (one for real robot and one for sim) or make it clear that users should set that parameter when using SCS/Gazebo.