LONDON, Sept 15 (Reuters) – British authorities announced on Monday that they have decided to drop the charges against two men, one of whom had been employed as a researcher for a senior member of Parliament, who were accused of spying for China. The individuals, Christopher Cash, 30, a former aide, and Christopher Berry, 33, both citizens of the UK, had faced allegations of sharing information that was harmful to national interests, infringing upon the Official Secrets Act, during the period