Fix undefined variable error in payment_service.py

- Alias 'authorizenet.constants' to 'auth_net_constants' to avoid conflict/confusion with 'constants' variable

app/services/payment_service.py

@@ -19,7 +19,7 @@ from authorizenet.apicontrollers import (
     createCustomerPaymentProfileController,
     getCustomerProfileController
 )
-from authorizenet.constants import constants
+from authorizenet.constants import constants as auth_net_constants
 from .. import schemas
 from ..constants import TransactionStatus, TransactionType, STATE_ID_TO_ABBREVIATION
 from ..utils import sanitize_input
@@ -33,7 +33,7 @@ from config import load_config, API_LOGIN_ID, TRANSACTION_KEY, VALIDATION_MODE,
 ApplicationConfig = load_config()
 
 # Set environment
-constants.environment = ENVIRONMENT
+auth_net_constants.environment = ENVIRONMENT