Since the rewriting of the views in OWL2, it is not possible to clear a set many2one field. In this commit, we restore the clear button. Steps to reproduce: * Go to Sales (on Mobile) * Create a new Quotation * Select a customer * Try to remove the selected customer => BUG closes odoo/odoo#109531 X-original-commit: 57cb2a34c8211352baa439ee784dc370cc6abb1b Signed-off-by: Pierre Paridans (app) <app@odoo.com> Signed-off-by: Romeo Fragomeli (rfr) <rfr@odoo.com>