tests/models: use d.copy() instead of dict(d)
for better clarity on the code author's intention.
Test Plan
Depends on !90 (closed).
Migrated from D2816 (view on Phabricator)
Staging instance, all changes can be removed at any time
for better clarity on the code author's intention.
Depends on !90 (closed).
Migrated from D2816 (view on Phabricator)