How do I know that? Well, multiple sources say that a layer of 'electrically charged plasma' develops around the ship.
Since the plasma is electrically charged (highly charged), some of that charge will be transferred to the hull of the vehicle.
I couldn't find any info on the amount of charge generated, but I'm sure it's quite high considering the forces involved.
I found a paper on the subject of 'Spacecraft Charging and Hazards to Electronics in Space' - which seems to be exactly what we're looking for. It primarily deals with the effects of this plasma and charges in orbit, but much of the information is relevant to reentry also.