feat: Deny course staff visibility of legacy courseware. (#27469)

Currently, course staff can always view their courses
in the Legacy courseware experience.

With this change, course staff will *not* be able
to view their courses if the New (MFE) courseware
experience has been enabled for them.

This does not affect global staff, and it does not
affect courses that are still running in the Legacy
experience.

Adds a new parameter returned by the course metadata API
used by the courseware MFE to determine if the button to
show legacy experience should be displayed or not.

TNL-8203

openedx/core/djangoapps/courseware_api/serializers.py

@@ -104,6 +104,7 @@ class CourseInfoSerializer(serializers.Serializer):  # pylint: disable=abstract-
     verified_mode = serializers.DictField()
     show_calculator = serializers.BooleanField()
     original_user_is_staff = serializers.BooleanField()
+    can_view_legacy_courseware = serializers.BooleanField()
     is_staff = serializers.BooleanField()
     can_load_courseware = serializers.DictField()
     notes = serializers.DictField()

openedx/core/djangoapps/courseware_api/views.py

@@ -33,7 +33,11 @@ from lms.djangoapps.courseware.courses import check_course_access
 from lms.djangoapps.courseware.masquerade import setup_masquerade
 from lms.djangoapps.courseware.module_render import get_module_by_usage_id
 from lms.djangoapps.courseware.tabs import get_course_tab_list
-from lms.djangoapps.courseware.toggles import courseware_mfe_is_visible, course_exit_page_is_active
+from lms.djangoapps.courseware.toggles import (
+    courseware_legacy_is_visible,
+    courseware_mfe_is_visible,
+    course_exit_page_is_active
+)
 from lms.djangoapps.courseware.views.views import get_cert_data
 from lms.djangoapps.grades.api import CourseGradeFactory
 from lms.djangoapps.verify_student.services import IDVerificationService
@@ -93,6 +97,10 @@ class CoursewareMeta:
         self.is_staff = has_access(self.effective_user, 'staff', self.overview).has_access
         self.enrollment_object = CourseEnrollment.get_enrollment(self.effective_user, self.course_key,
                                                                  select_related=['celebration', 'user__celebration'])
+        self.can_view_legacy_courseware = courseware_legacy_is_visible(
+            course_key=course_key,
+            is_global_staff=self.original_user_is_global_staff,
+        )
 
     def __getattr__(self, name):
         return getattr(self.overview, name)
@@ -386,6 +394,7 @@ class CoursewareInformation(RetrieveAPIView):
         * can_load_course: Whether the user can view the course (AccessResponse object)
         * is_staff: Whether the effective user has staff access to the course
         * original_user_is_staff: Whether the original user has staff access to the course
+        * can_view_legacy_courseware: Indicates whether the user is able to see the legacy courseware view
         * user_has_passing_grade: Whether or not the effective user's grade is equal to or above the courses minimum
             passing grade
         * course_exit_page_is_active: Flag for the learning mfe on whether or not the course exit page should display