do not write restart at end of erc test

Author: jedwards4b

cime_config/buildnml

@@ -43,6 +43,7 @@ def _create_drv_namelists(case, infile, confdir, nmlgen, files):
     config["MACH"] = case.get_value("MACH")
     config["MPILIB"] = case.get_value("MPILIB")
     config["OS"] = case.get_value("OS")
+    config["TESTCASE"] = case.get_value("TESTCASE")
     config["glc_nec"] = (
         0 if case.get_value("GLC_NEC") == 0 else case.get_value("GLC_NEC")
     )

cime_config/namelist_definition_drv.xml

@@ -2862,12 +2862,13 @@
       forces a restart write at the end of the run in addition to any
       setting associated with rest_option.  default=true.  this setting
       will be set to false if restart_option is none or never.
-      default: false
+      default: true
     </desc>
     <values>
       <value>.true.</value>
       <value rest_option='none'>.false.</value>
       <value rest_option='never'>.false.</value>
+      <value TESTCASE='ERC'>.false.</value>
     </values>
   </entry>