BEIJING: Jackie Chan might still be popular in China, but nowadays the pro-Beijing actor is as well-known as fodder for jokes as he is for his gritty martial arts and slapstick humor on screen. His latest contribution to the country’s mass culture and entertainment: “duang.”It’s not a word, but a sound he made in an old TV commercial meaning something like “ta-da!” A new mash-up video of the old ad has made “duang” a trending topic on China’s social media.The sound began circulating days before the rubberstamp legislature was called into session this week, and some observers see it as a way...