LONDON (Reuters) - Oil prices rose on Friday and held on track for their first weekly gain since early January as investors bet the economic impact of the coronavirus would be short-lived and hoped for further Chinese central bank stimulus to tackle any slowdown.Brent crude was up 57 cents or 1% at $56.91 a barrel by 1024 GMT. It has risen 4.4% since last Friday, its first weekly increase in six weeks. U.S. West Texas Intermediate (WTI) was 48 cents or 0.9% higher at $51.90 a barrel, up 3.2%..