posix-configs: Update optical flow SITL test parameter defaults
posix-configs: Update optical flow SITL test parameter defaults

Use baro for height in EKF.
Use terrain hold mode in height controller.

dagar/Firmware,PX4/Firmware,Aerotenna/Firmware,dagar/Firmware,acfloria/Firmware,PX4/Firmware,dagar/Firmware,Aerotenna/Firmware,Aerotenna/Firmware,mje-nz/PX4-Firmware,PX4/Firmware,mje-nz/PX4-Firmware,mje-nz/PX4-Firmware,acfloria/Firmware,krbeverx/Firmware,Aerotenna/Firmware,krbeverx/Firmware,mje-nz/PX4-Firmware,krbeverx/Firmware,dagar/Firmware,mje-nz/PX4-Firmware,krbeverx/Firmware,PX4/Firmware,krbeverx/Firmware,PX4/Firmware,PX4/Firmware,acfloria/Firmware,PX4/Firmware,acfloria/Firmware,acfloria/Firmware,dagar/Firmware,acfloria/Firmware,Aerotenna/Firmware,mje-nz/PX4-Firmware,Aerotenna/Firmware,Aerotenna/Firmware,krbeverx/Firmware,dagar/Firmware,acfloria/Firmware,mje-nz/PX4-Firmware,dagar/Firmware,krbeverx/Firmware