BERLIN, July 23 (Reuters) - Almost one in three Germans below the age of 30 believes the U.S. government may have sponsored the September 11, 2001, attacks on New York and Washington, according to a poll published on Wednesday. And about 20 percent of Germans in all age groups hold this view, a survey of 1,000 people conducted for the weekly Die Zeit said. It also said 68 percent of all Germans felt the media had not reported the full truth behind the attacks, in which some 3,000 people were killed when hijacked planes were crashed into the World Trade...