It's not as if human driven cars never get stuck in an intersection. I imagine the solution will be much the same: it will be moved manually if possible or towed if not. If a person is deliberately fucking with traffic by deliberately messing with an autonomous car, they'll also probably be fined.

I mean the other day on my daily commute there were two cars right in the middle of a freeway, one attempting to jump start the other and they were at it for a while. This is not shockingly new ground.