Publishes a draft, as Publish in Owner Statements does: the report is computed once more and frozen, and the bookings and expenses it counts can't be counted by another report. It can't be unpublished or changed afterwards, and it isn't emailed to the owner. An expense changed after publishing doesn't change the report (isReported on Get Expenses). Returns 409 when the report is no longer a draft, or when another published report already counts some of its bookings. Requires the ownerStatements:write scope.