REVEM-239 Add audit access expiration deadline to user-metadata

lms/djangoapps/ccx/tests/test_field_override_performance.py

lms/djangoapps/courseware/tests/test_course_info.py

lms/djangoapps/courseware/tests/test_views.py

lms/djangoapps/experiments/utils.py

lms/templates/experiments/user_metadata.html

...eatures/course_experience/tests/views/test_course_home.py

...ures/course_experience/tests/views/test_course_updates.py