Imagine, if you can, a time before the DVR, before Netflix, before Hulu. A time when watching TV still consisted of (shudder) flipping channels. The prospect of going back to the “is anything on?” past may provoke near-panic in viewers accustomed to watching what they want when they want it, but the sensation of keeping a finger firmly pressed to the channel changer, hunting for better entertainment prey, can be revisited in more genial surroundings with “Kroll Show,” which just wrapped its second season on Comedy Central.