Deprecate ExperimentWaffleFlag.override method

This is part of a removal of the many override methods of toggle
flag/namespace classes. This allows us to remove imports of test modules
from production code.

openedx/features/personalized_learner_schedules/show_answer/tests/test_show_answer_override.py

@@ -1,7 +1,6 @@
 """Tests for Show Answer overrides for self-paced courses."""
 
 import ddt
-
 from django.test import RequestFactory
 from django.test.utils import override_settings
 
@@ -9,6 +8,7 @@ from common.lib.xmodule.xmodule.capa_base import SHOWANSWER
 from lms.djangoapps.ccx.tests.test_overrides import inject_field_overrides
 from lms.djangoapps.courseware.model_data import FieldDataCache
 from lms.djangoapps.courseware.module_render import get_module
+from lms.djangoapps.experiments.testutils import override_experiment_waffle_flag
 from openedx.features.course_experience import RELATIVE_DATES_FLAG
 from xmodule.modulestore.tests.django_utils import ModuleStoreTestCase
 from xmodule.modulestore.tests.factories import CourseFactory
@@ -36,7 +36,7 @@ class ShowAnswerFieldOverrideTest(ModuleStoreTestCase):
 
     @ddt.data(True, False)
     def test_override_enabled_for(self, active):
-        with RELATIVE_DATES_FLAG.override(active=active):
+        with override_experiment_waffle_flag(RELATIVE_DATES_FLAG, active=active):
             # Instructor paced course will just have the default value
             ip_course = self.setup_course()
             course_module = self.get_course_module(ip_course)
@@ -63,7 +63,7 @@ class ShowAnswerFieldOverrideTest(ModuleStoreTestCase):
         (SHOWANSWER.ALWAYS, SHOWANSWER.ALWAYS),
     )
     @ddt.unpack
-    @RELATIVE_DATES_FLAG.override(active=True)
+    @override_experiment_waffle_flag(RELATIVE_DATES_FLAG, active=True)
     def test_get(self, initial_value, expected_final_value):
         course = self.setup_course(self_paced=True, showanswer=initial_value)
         course_module = self.get_course_module(course)