TEZ-1689. addendum - fix unit test failure. (zjffdu)

(cherry picked from commit 1ffbc1935646f7c422b551e6e0ffdc001311d074)
TEZ-1666. UserPayload should be null if the payload is not specified.
(sseth)
(cherry picked from commit 4e69bed5c7dbc68d17f3d4648838e5acfc52c3eb)
TEZ-1699. Vertex.setParallelism should throw an exception for invalid invocations (bikas)
(cherry picked from commit 06e9f88eb207f00ae2f31f46477001726754115c)
TEZ-1700. Replace containerId from TaskLocationHint with [TaskIndex+Vertex] based affinity (bikas)
(cherry picked from commit 74c7f874d558f933fbf9697c537d204eb56806c9)