Migration to 16.0 deactivates group_stock_production_lot

[sergiocorato]

Module

stock, maybe base

Describe the bug

group_stock_production_lot is no more active after migration from a v. 14 to a v. 16

To Reproduce

Affected versions:
16.0

Steps to reproduce the behavior:

1. enable group_stock_production_lot in v. 14.0
2. migrate to v. 16.0

Expected behavior
group_stock_production_lot is active

Additional context
This field hadn't a default in v. 14.0 of group, now it's group="base.group_user,base.group_portal". If in the instance only base.group_user have the group group_production_lot enabled, the field group_stock_production_lot is inactive by default.
I don't know how these cases are managed in openupgrade process.