BEIJING — Authorities using a robotic submarine to look for wreckage of Malaysia Airlines flight 370 said Saturday they expect to complete the search of the “focused underwater area” in five to seven days. Shortly after officials decided Monday to deploy the U.S. Navy’s Bluefin-21 robotic sub in the Indian Ocean, Navy representatives said the mission could take six weeks to two months as the unmanned vehicle crawled over the seabed, using sonar to map an area about as big as the city of Los Angeles. However, Australian authorities coordinating the search from a base in Perth said Saturday that the search area was now defined as a circle with a radius of 10 kilometers…