Add translator comments

There are English words in these strings, but they are actually specific
values that must appear as these English words, and so should not be
translated.

common/lib/xmodule/xmodule/modulestore/inheritance.py

@@ -89,9 +89,12 @@ class InheritanceMixin(XBlockMixin):
         help=_("Enter the ids for the content groups this problem belongs to."),
         scope=Scope.settings,
     )
+
     showanswer = String(
         display_name=_("Show Answer"),
         help=_(
+            # Translators: DO NOT translate the words in quotes here, they are
+            # specific words for the acceptable values.
             'Specify when the Show Answer button appears for each problem. '
             'Valid values are "always", "answered", "attempted", "closed", '
             '"finished", "past_due", "correct_or_past_due", and "never".'
@@ -102,10 +105,12 @@ class InheritanceMixin(XBlockMixin):
     rerandomize = String(
         display_name=_("Randomization"),
         help=_(
+            # Translators: DO NOT translate the words in quotes here, they are
+            # specific words for the acceptable values.
             'Specify the default for how often variable values in a problem are randomized. '
-            'This setting should be set to \"never\" unless you plan to provide a Python '
+            'This setting should be set to "never" unless you plan to provide a Python '
             'script to identify and randomize values in most of the problems in your course. '
-            'Valid values are \"always\", \"onreset\", \"never\", and \"per_student\".'
+            'Valid values are "always", "onreset", "never", and "per_student".'
         ),
         scope=Scope.settings,
         default="never",

lms/djangoapps/lms_xblock/mixin.py

@@ -43,6 +43,8 @@ class LmsBlockMixin(XBlockMixin):
     )
     chrome = String(
         display_name=_("Courseware Chrome"),
+        # Translators: DO NOT translate the words in quotes here, they are
+        # specific words for the acceptable values.
         help=_("Enter the chrome, or navigation tools, to use for the XBlock in the LMS. Valid values are: \n"
                "\"chromeless\" -- to not use tabs or the accordion; \n"
                "\"tabs\" -- to use tabs only; \n"