This testdef is used to test a stealth feature in mpaso introduced by
PR #6802. It uses mpaso namelist variables to turn on the
frazil_ice_porosity model:
   config_use_frazil_ice_porosity = .true.
and set the frazil_ice_porosity to 1:
   config_frazil_ice_porosity = 1.0
It will have an impact on all mpaso runs.
