sd-device: also store properties read from udev database to sd_device::properties_db

sd-device: also store properties read from udev database to sd_device::properties_db

Follow-up for a3ce813697bcc1c4644e097a2f1cd0459326d6ee and
5ce41697bd3ddc19cd6e1e6834751082ca0c8b02.

Before a3ce813697bcc1c4644e097a2f1cd0459326d6ee, all properties in
src->properties and src->properties_db are mixed and copied to
dst->properties_db by device_copy_properties().
So, it is not necessary to store data from udev database file to
sd_device::properties_db before copying properties.

But now, properties are not mixed. So, the read data need to be
stored to also ::properties_db.

Fixes #11721.