By Kanishka Singh and Mike ScarcellaWASHINGTON, March 16 (Reuters) - A federal jury in Los Angeles convicted a former Syrian government official, who headed the Damascus Central Prison under the government of ousted Syrian President Bashar al-Assad, of torture, the U.S. Justice Department said on Monday.Samir Ousman Alsheikh, 73, was convicted on one count of conspiracy to commit torture and three counts of torture for his involvement in the torture of prisoners at Adra Prison as it is colloquia...