Add known_hosts entries for additional Gerrit keys
Add known_hosts entries for additional Gerrit keys

Gerrit has shuffled the order in which it returns host keys, and
ssh clients can get confused if the first host key type they support
in the list isn't included in the known_hosts file already. Just go
ahead and include all the host keys our Gerrit provides.

Change-Id: I15cdf24d9b3a372a7c8ad1aef97baa3b5eeefab0

openstack-infra/project-config,openstack-infra/project-config