By Arathy Somasekhar HOUSTON (Reuters) -Oil prices were steady after hitting a three-week high on Tuesday as restarts at some U.S. energy plants shut by winter storms offset gains stemming from hopes of a demand recovery as China eases its COVID-19 restrictions. Brent crude was up 41 cents, or 0.5%, at $84.33 a barrel, while U.S. West Texas Intermediate crude settled 3 cents lower at $79.53 per barrel. Both benchmarks hit their highest level since Dec. 5 earlier in the session. UK and U.S. markets were closed on Monday for the Christmas holiday. Refineries along the Gulf Coast began to resume …