[SEBA-218] Making ONU serial number handling case insensitive

Change-Id: I7cd42041709c5e8041959da84c7e1853a8ba0636
diff --git a/xos/synchronizer/model_policies/test_model_policy_att_workflow_driver_serviceinstance.py b/xos/synchronizer/model_policies/test_model_policy_att_workflow_driver_serviceinstance.py
index 774efda..c47738d 100644
--- a/xos/synchronizer/model_policies/test_model_policy_att_workflow_driver_serviceinstance.py
+++ b/xos/synchronizer/model_policies/test_model_policy_att_workflow_driver_serviceinstance.py
@@ -200,7 +200,7 @@
     def test_subscriber_enable_status_auth_state_approved(self):
         self.si.valid = "valid"
         self.si.backend_code = 1
-        self.si.serial_number = "BRCM1234"
+        self.si.serial_number = "brcm1234"
         self.si.onu_state = "ENABLED"
         self.si.authentication_state = "APPROVED"
 
@@ -210,7 +210,7 @@
         )
 
         subscriber = RCORDSubscriber(
-            onu_device=self.si.serial_number,
+            onu_device="BRCM1234",
             status='awaiting-auth'
         )