General Dynamics Corp. will build the next batch of oilers and help design the next generation of amphibious warships under a U.S. Navy contract that could be worth more than $3 billion. The award, announced Thursday, calls for the Falls Church-based defense giant to build and deliver up to six TAO-205 Class Fleet Replenishment Oilers, with the first being procured in fiscal 2016 and the next five between fiscal 2018 and 2022 — that is, if all options are exercised. Additionally, the company…