origin_metadata_add: Reject non-bytes types for 'metadata'.
The left-over jsonize() allowed passing a dict under some circumstances, which allowed tests to pass but failed in production.
Migrated from D3168 (view on Phabricator)
The left-over jsonize() allowed passing a dict under some circumstances, which allowed tests to pass but failed in production.
Migrated from D3168 (view on Phabricator)