is_rental_order is a computed field, not passed in vals during create.
Use in_rental_app context flag in create() and add onchange handler
so sale type sets to 'Rentals' immediately when toggled in the form.
Made-with: Cursor
Rental orders no longer show the "Authorizer Required?" question or
the Authorizer field. The sale type is automatically set to 'Rentals'
when creating or confirming a rental order. Validation logic also
skips authorizer checks for rental sale type.
Made-with: Cursor
