With the flag, ipvs uses both source IP and source port (instead of
only source IP) to distribute new connections evently to endpoints
that avoids sending all connections from the same client (i.e. same
source IP) to one single endpoint.
User can explicitly set sessionAffinity in service spec to keep all
connections from a source IP to end up on the same endpoint if needed.
Change-Id: I42f950c0840ac06a4ee68a7bbdeab0fc5505c71f