The ISS does get hit by small debris quite often. You can see evidence of it in photos of the windows etc.
Pieces of debris which are deemed large enough to possibly cause a major breach are generally large enough to be tracked. When one of these larger objects is calculated to come within a certain unsafe distance of the station either they attempt to change the orbit of the ISS so that it will pass safely or, if it's too late for a manuver, the crew suit up and enter their Soyuz spacecraft, ready to undock and potentially deorbit, and wait until the object has safely passed. This has happened a few times during the life of the station.
What happens in the film could happen, though not in the way it is depicted. In the film a satellite in GEO is destroyed and most of its debris is all of a sudden crossing the orbit of the HST+Shuttle. You could do the maths properly but in reality it would take many hours for that debris to reach them, probably at least 10 hours, maybe a few bits sooner. And when it did reach them it wouldn't all be all together, the pieces would be very spread out - still very dangerous of course but it wouldn't have torn through them like shrapnel. In reality they would have plenty of time to safely deorbit.
I won't go into all the other things wrong with the way orbital flight is depicted in the film (like since when are the HST, the ISS and Tiangong 1 in even remotely similar orbits... wtf) but I will say that once I realised I needed to turn my brain off I did very much enjoy the visual spectacle of the film, and have a couple of more times since
