Provide 2nd set of defaults for CollisionFreeSpeedModelV1/V2

[Ozaq]

In #1306 @Carole1004 and @JetteSchumann analysed the impact of larger time steps on the velocity model. The proposed parameter set works well with $\Delta{t}=0.02s$ which doubles our step length. With this parameter set it should be possible to produce similar qualitative results as with the default parameter set in half the time.