Can't add Cisco ASA "admin" context

I'm bringing up a new Cisco fpr-3120 (running ASA code).  I'm trying to add the device to AKIPS via SNMPv3, but it's failing with the following error:

sysName "admin" clashes with username

I haven't found a way to change the sysName on the ASA to include the full system name and not just the context name.
Is there a way to monitor the "admin" context of an ASA?