Fix the inner order of switchBehavior in RaftAcotr

updateAndPersist should be called before switchBehavior.
Otherwise, when the EntityOwnershipShard trigger a new write transaction
in onLeaderChanged base on last term, It will lead to fail in this
transaction because of the term value is inconsistent between AppendEntries
and AppendEntriesReply

Change-Id: I9118f7ec283f23e02dc285ccf6a3fbbce47dc508
Signed-off-by: HeYunBo <he.yunbo@zte.com.cn>