[fleet] New API migration

- Task: https://www.odoo.com/web#id=10075&view_type=form&model=project.task&action=333&active_id=131
- Pad: https://pad.odoo.com/p/r.xFp6558VZvondGaA
if you have to block the user here, raise a an exception (warning, error...)

assertions are not made to indicate errors, it is only a safety net for the programmer