there is no way to update the productId for an arrangement

[vladirimia-iss]

When updating an arrangement, according to documentation, updating the externalProductId is actually done through productId field (externalProductId doesn't exist on update):
https://developer.backbase.com/apis/specs/arrangement-manager/arrangement-service-api/2.5.0/operations/Arrangements/putArran
gements/
Now the externalProductId of the arrangement doesn't get updated because the field is not mapped in
com.backbase.stream.product.mapping.ProductMapper, and there is no way to map this:

AccountArrangementItemPut toArrangementItemPut(AccountArrangementItemPost var1);

it should be mapped from externalProductId from POST to productId to PUT.

I can create PR but i don't have access.