Covenant contradicted the ancient xenomorphs Out of the Shadows, unless you follow the fan theories that David didn't create the aliens, (which I'm pretty sure Andrew Gaska subscribes to). So it can still be canon if you reject David as the creator and are willing to swallow the contrived idea that Ripley had another adventure in between Alien and Aliens.
Sea of Sorrows is a sequel to Out of the Shadows, so same goes for that one.
River of Pain has a lot of continuity errors with Aliens. The most annoying part for me is the concept that there was already a squad of colonial marines at Hadley's Hope before the takeover and the film doesn't mention it at all. If you're willing to swallow that, River of Pain can be canon too.
I haven't read Rage Wars.