This patchset cleans up the peer start process by moving the gossip
service init process separately in a single method.

There will be several following-up patchsets to improve the entire start
process of the peer node. Keep each change small and focused.

Change-Id: Id59ba860e140f354991b3874c140993c39a190cb
Signed-off-by: Baohua Yang <yangbaohua@gmail.com>