WASHINGTON — President Trump arrived in Beijing on Wednesday without a tarmac greeting from Chinese President Xi Jinping — but the seeming snub was actually an “upgrade” from his last welcome in 2017, according to an expert. “It’s actually quite revealing from a protocol perspective,” said Isabelle Vladoiu, founder of the US Institute of Diplomacy and Human Rights. “Xi Jinping did not personally greet Trump at the airport in 2017 either, but this time Beijing noticeably upgraded the reception