[lib] Add threadInfoFromRawThreadInfo test to thread-utils.test
Summary:
Based on feedback here: https://phab.comm.dev/D10718?id=35839#inline-65319
Depends on D10812
Test Plan: Unit test passes.
Reviewers: ashoat, ginsu, tomek
Reviewed By: ashoat
Subscribers: rohan
Differential Revision: https://phab.comm.dev/D10818