By James Pomfret HONG KONG (Reuters) – A coalition of Christians and Catholics on Monday called on Hong Kong leader Carrie Lam to drop charges against media tycoon Jimmy Lai and other political activists jailed or in custody under a China-imposed national security law. The petition by more than a dozen Christian and Catholic groups and leaders was handed to a government representative outside Hong Kong’s government headquarters. “She could be active in asking Beijing (for an amnesty),” said Catholic priest Franco Mella, referring to Hong Kong’s leader Carrie Lam, who is a devout Catholic. “Let…