Update glacier_region namelist items for new GLACIER_REGIONS

We are removing the old second region (in CISM's Greenland domain but
outside Greenland itself). So updating the namelist defaults to align
with this removal.

bld/namelist_files/namelist_defaults_ctsm.xml

@@ -466,30 +466,27 @@ attributes from the config_cache.xml file (with keys converted to upper-case).
 
 <!-- Default glacier behavior is:
      Mountain glaciers: single_at_atm_topo
-     Greenland - inside CISM grid but outside Greenland itself: virtual
-     Greenland itself: virtual
+     Greenland: virtual
      Antarctica: multiple
 
      If CISM is running over Antarctica, then we change the Antarctica
      behavior to virtual. Note that the Greenland behavior is always
      virtual, even if Greenland isn't included in this run.
 -->
-<glacier_region_behavior glc_use_antarctica="0">'single_at_atm_topo','virtual','virtual','multiple'</glacier_region_behavior>
-<glacier_region_behavior glc_use_antarctica="1">'single_at_atm_topo','virtual','virtual','virtual' </glacier_region_behavior>
+<glacier_region_behavior glc_use_antarctica="0">'single_at_atm_topo','virtual','multiple'</glacier_region_behavior>
+<glacier_region_behavior glc_use_antarctica="1">'single_at_atm_topo','virtual','virtual' </glacier_region_behavior>
 
 <!-- Default glacier melt behavior is:
      Mountain glaciers: remains_in_place
-     Greenland - inside CISM grid but outside Greenland itself: replaced_by_ice
-     Greenland itself: replaced_by_ice
+     Greenland: replaced_by_ice
      Antarctica: replaced_by_ice -->
-<glacier_region_melt_behavior>'remains_in_place','replaced_by_ice','replaced_by_ice','replaced_by_ice'</glacier_region_melt_behavior>
+<glacier_region_melt_behavior>'remains_in_place','replaced_by_ice','replaced_by_ice'</glacier_region_melt_behavior>
 
 <!-- Default glacier ice runoff behavior is:
      Mountain glaciers: melted
-     Greenland - inside CISM grid but outside Greenland itself: melted
-     Greenland itself: remains_ice
+     Greenland: remains_ice
      Antarctica: remains_ice -->
-<glacier_region_ice_runoff_behavior>'melted','melted','remains_ice','remains_ice'</glacier_region_ice_runoff_behavior>
+<glacier_region_ice_runoff_behavior>'melted','remains_ice','remains_ice'</glacier_region_ice_runoff_behavior>
 
 <!-- This parameter is tied (in a scientific sense) to h2osno_max: For large
      values of h2osno_max, glc_snow_persistence_max_days should be 0; for small

cime_config/SystemTests/lvg.py

@@ -32,12 +32,12 @@ def _case_one_setup(self):
         append_to_user_nl_files(
             caseroot=self._get_caseroot(),
             component="clm",
-            contents="glacier_region_behavior = 'single_at_atm_topo', 'virtual', 'virtual', 'multiple'",
+            contents="glacier_region_behavior = 'single_at_atm_topo', 'virtual', 'multiple'",
         )
 
     def _case_two_setup(self):
         append_to_user_nl_files(
             caseroot=self._get_caseroot(),
             component="clm",
-            contents="glacier_region_behavior = 'single_at_atm_topo', 'virtual', 'virtual', 'virtual'",
+            contents="glacier_region_behavior = 'single_at_atm_topo', 'virtual', 'virtual'",
         )

cime_config/usermods_dirs/_includes/cmip6_glaciers_virtual_antarctica/user_nl_clm

@@ -5,5 +5,5 @@
 ! This differs from the default in that it turns on virtual columns over Antarctica
 ! This is desired so that we have the output needed to drive a later offline CISM Antarctica simulation
 ! However, this increases the cost of CLM by about 10%
-glacier_region_behavior = 'single_at_atm_topo', 'virtual', 'virtual', 'virtual'
+glacier_region_behavior = 'single_at_atm_topo', 'virtual', 'virtual'