[FIX] Issue of wrong uom conversion in pack operation.

Hello ,

I have fix issue of wrong uom conversion in pack operation.

For example:
We have two products : Product A(KG) and product B(GM)
If we buy this product with ...( Product A in (GM) and Product B in (KG) )
Result in pack operation :(Product A in (GM) and Product B in (GM))
Expected result in pack operation: (Product A in (KG) and Product B in (GM))

Issue raised due worng comparision of factor: (move.product_uom.factor > product_uom[move.product_id.id])

Thanks.