Answer changing tag to modify snow thermal conductivity defaults

[wwieder]

Need an answer changing tag that sets namelist defaults for CLM6 physics to turn on Jordan over glacier land units (and use Sturm everywhere else).

 snow_thermal_cond_glc_method = 'Jordan1991'
 snow_thermal_cond_lake_method = 'Sturm1997'
 snow_thermal_cond_method = 'Sturm1997'

This needs to be confirmed with CAM team and CESM project meeting.

[wwieder]

This is required for our alpha07 tag

[slevis-lmwg]

For sprint accounting purposes I'm marking this done. I resolved it with the first commit to https://github.com/ESCOMP/CTSM/pull/3206. We will not close the issue until we merge to master.