No, this is a false cognate. Chinese bāo (包) is short for miànbāo (麵包), literally meaning "flour wrap/package", and its use has been attested since the Song Dynasty (ca. 11th century), whereas the Portuguese didn't have contact with China until the 16th century. The pronunciation of 包 at that time was still mostly similar to what it is today – using IPA notation, it is reconstructed as /pˠau/, compared to /pau̯/ today.
