use os._exit to kill process on session expiry with zookeeper.
Change-Id: If3603ba494975a2fd8f4d09adf9df1f5094cc327
Merge "use os._exit to kill process on session expiry with zookeeper. Change-Id: If3603ba494975a2fd8f4d09adf9df1f5094cc327" into R1.06