As Hong Kong’s biggest banks prepare to report their 2019 results beginning next week, investors will be closely watching to see how HSBC Holdings and its peers expect the coronavirus outbreak to hit their bottom lines this year.The early signs are worrisome as the health crisis hurts local businesses and consumers in an economy already wrecked by months of anti-government protests last year. Banking sector revenue is expected to be “very weak” in the first half as the viral outbreak cools loan…