Move test_get_all_courses_by_mobile_available to CourseOverviewTestCase

It somehow ended up in CourseOverviewImageSetTestCase (merge artifact?).

openedx/core/djangoapps/content/course_overviews/tests.py

@@ -494,6 +494,27 @@ class CourseOverviewTestCase(ModuleStoreTestCase):
             {c.id for c in org_courses[1]},
         )
 
+    def test_get_all_courses_by_mobile_available(self):
+        non_mobile_course = CourseFactory.create(emit_signals=True)
+        mobile_course = CourseFactory.create(mobile_available=True, emit_signals=True)
+
+        test_cases = (
+            (None, {non_mobile_course.id, mobile_course.id}),
+            (dict(mobile_available=True), {mobile_course.id}),
+            (dict(mobile_available=False), {non_mobile_course.id}),
+        )
+
+        for filter_, expected_courses in test_cases:
+            self.assertEqual(
+                {
+                    course_overview.id
+                    for course_overview in
+                    CourseOverview.get_all_courses(filter_=filter_)
+                },
+                expected_courses,
+                "testing CourseOverview.get_all_courses with filter_={}".format(filter_),
+            )
+
 
 @ddt.ddt
 class CourseOverviewImageSetTestCase(ModuleStoreTestCase):
@@ -863,24 +884,3 @@ class CourseOverviewImageSetTestCase(ModuleStoreTestCase):
                 }
             )
             return course_overview
-
-    def test_get_all_courses_by_mobile_available(self):
-        non_mobile_course = CourseFactory.create(emit_signals=True)
-        mobile_course = CourseFactory.create(mobile_available=True, emit_signals=True)
-
-        test_cases = (
-            (None, {non_mobile_course.id, mobile_course.id}),
-            (dict(mobile_available=True), {mobile_course.id}),
-            (dict(mobile_available=False), {non_mobile_course.id}),
-        )
-
-        for filter_, expected_courses in test_cases:
-            self.assertEqual(
-                {
-                    course_overview.id
-                    for course_overview in
-                    CourseOverview.get_all_courses(filter_=filter_)
-                },
-                expected_courses,
-                "testing CourseOverview.get_all_courses with filter_={}".format(filter_),
-            )