Add option on employees to exclude from mass allocation

hr_holidays_usability/hr_employee_view.xml

@@ -12,9 +12,16 @@
     <field name="model">hr.employee</field>
     <field name="inherit_id" ref="hr_holidays.view_employee_form_leave_inherit"/>
     <field name="arch" type="xml">
+        <!-- too difficult to hide the inside of the Leave group
+        so I hide the whole group and re-create one -->
         <group string="Leaves" position="attributes">
             <attribute name="invisible">1</attribute>
         </group>
+        <group string="Leaves" position="after">
+            <group name="holidays" string="Holidays">
+                <field name="holiday_exclude_mass_allocation"/>
+            </group>
+        </group>
     </field>
 </record>