Redfish: Fix for 'Verify Error Upon Creating Same Users With Different Privileges'

Changes:
    - In /redfish/account_service/test_user_account.robot
    - RoleId with 'Operator' no more exist, Hence modifying RoleId value to 'ReadOnly'.

Tested: - Verify_Error_Upon_Creating_Same_Users_With_Different_Privileges

Change-Id: I787c5f880797290c97eab94f2ed33aff155f764f
Signed-off-by: Nandish-Matti <nandish.matti@ibm.com>
diff --git a/redfish/account_service/test_user_account.robot b/redfish/account_service/test_user_account.robot
index 72f7607..5654315 100644
--- a/redfish/account_service/test_user_account.robot
+++ b/redfish/account_service/test_user_account.robot
@@ -201,7 +201,7 @@
 
     # Create specified user.
     ${payload}=  Create Dictionary
-    ...  UserName=test_user  Password=TestPwd123  RoleId=Operator  Enabled=${True}
+    ...  UserName=test_user  Password=TestPwd123  RoleId=ReadOnly  Enabled=${True}
     Redfish.Post  /redfish/v1/AccountService/Accounts/  body=&{payload}
     ...  valid_status_codes=[${HTTP_BAD_REQUEST}]