OptionalmigrationThe migration to create. The server generates migration_id and sets state
to PLANNING_PENDING. Required fields: asset_type, asset_uri.
OptionalrequestClient-generated request ID for idempotent request deduplication. The server de-duplicates requests with the same request_id for at least 24 hours, returning the existing migration instead of creating a duplicate.
A request to create a new migration.