Support for Ocata-Pike live-migration over ssh

Support for Ocata-Pike live-migration over ssh

In Ocata all live-migration over ssh is performed on the default ssh port (22).
In Pike the containerized live-migration over ssh is on port 2022 as the
docker host's sshd is using port 22.

To allow live migration during upgrade we need to temporarily pin the Pike
computes to port 22 and in the final converge we can switch over to port 2022.

This also changes the default port to 2022 for baremetal computes in Pike to
enable live-migration between baremetal and containerized computes.

Change-Id: Icb9bfdd9a99dc1dce28eb95c50a9a36bffa621b1
Depends-On: I0b80b81711f683be539939e7d084365ff63546d3
Closes-Bug: 1714171
(cherry picked from commit 17fd16b9f266e1aa67bf03ebdf309e89d668ada2)