[lib] Add validator support for 'Unauthenticated' Tunnelbroker message
Summary:
Addresses ENG-8394.
The Unauthenticated enum variant was missing in client-side validator.
Added a comment to keep that in sync.
Test Plan:
- Hardcoded setUnauthorizedDeviceID(not-null-value) to keep Tunnelbroker connection anonymous.
- Called tunnelbrokerContext.sendMessage()
- Verified that invalid TunnelbrokerMessage is no longer occuring
Reviewers: kamil, ashoat
Reviewed By: kamil
Subscribers: tomek
Differential Revision: https://phab.comm.dev/D12418