UUID reset to None in id_perms
Root cause: If the PUT request doesn't contain the uuid in obj dict, new id_perms is created with default value. This would reset the UUID field
The request from UI would not contain the 'uuid' field in obj_dict in PUT request.

Change-Id: I80bbfcd4d1d99d28de566a423ceb1bf0d967ca46
Fix: Pass obj_uuid from PUT request to "_ensure_id_perms_present" instead of accessing the 'uuid' from obj_dict.