[bugfix] Account for 3-part node descriptions

[PaulJKim]

Summary of changes

Asana Ticket: Process ARINC JSON for LivePA connectivity into Splunk

After deploying the initial change, we lost logging of some device types. I think this is due to the description screen for these devices only having three parts to them rather than 4. Oddly, I'm not able to find any MatchError logs in Splunk which is what I would expect, but the Endpoint process is crashing every 2 minutes which is the cadence at which we receive device status logs.

Reviewer Checklist

• Meets ticket's acceptance criteria
• Any new or changed functions have typespecs
• Tests were added for any new functionality (don't just rely on Codecov)
• If signs.json was changed, there is a follow-up PR to signs_ui to update its dependency on this project
• This branch was deployed to the staging environment and is currently running with no unexpected increase in warnings, and no errors or crashes (compare on Splunk: staging vs. prod)