Automatic merge from submit-queue
Use the CNI bridge plugin to set hairpin mode
Following up this part of #23711:
> I'd like to wait until containernetworking/cni#175 lands and then just pass the request through to CNI.
The code here just
* passes the required setting down from kubenet to CNI
* disables `DockerManager` from doing hairpin-veth, if kubenet is in use
Note to test you need a very recent version of the CNI `bridge` plugin; the one brought in by #28799 should be OK.
Also relates to https://github.com/kubernetes/kubernetes/issues/19766#issuecomment-232722864
63602348a4