[FIX] sale_timesheet: onchange for product uom change po_uom

po_uom_id and uom_id should be from similar uom_group. It
was not the case by default using `'default_detailed_type': 'service'`.
This fix the issue

closes odoo/odoo#142887

X-original-commit: b557cc0831e2c6d0967c3d4420c1b89a0f5ce191
Signed-off-by: Xavier Bol (xbo) <xbo@odoo.com>

addons/sale_timesheet/models/product.py

@@ -83,6 +83,7 @@ class ProductTemplate(models.Model):
                 record.uom_id = record._origin.uom_id
             else:
                 record.uom_id = self._get_default_uom_id()
+            record.uom_po_id = record.uom_id
 
     def _get_service_to_general_map(self):
         return {
@@ -149,6 +150,7 @@ class ProductProduct(models.Model):
                 record.uom_id = record._origin.uom_id
             else:
                 record.uom_id = self._get_default_uom_id()
+            record.uom_po_id = record.uom_id
 
     @api.onchange('service_policy')
     def _onchange_service_policy(self):