Added app.py to mobile_api to resolve migration issue (#25327)

removed un-necessary imports

lms/djangoapps/mobile_api/apps.py

@@ -0,0 +1,14 @@
+"""
+Configuration for the mobile_api Django application.
+"""
+
+
+from django.apps import AppConfig
+
+
+class MobileApiConfig(AppConfig):
+    """
+    Configuration class for the mobile_api Django application.
+    """
+    name = 'lms.djangoapps.mobile_api'
+    verbose_name = "Mobile API"

lms/envs/common.py

@@ -2589,7 +2589,7 @@ INSTALLED_APPS = [
     'django_countries',
 
     # edX Mobile API
-    'mobile_api',
+    'lms.djangoapps.mobile_api.apps.MobileApiConfig',
     'social_django',
 
     # Surveys