Jenkins slaves use ssh to communicate with the master node. The
sshd process used to perform this communication should be in the same
unlimited cgroup as jenkins:java. Make it so.
This protects the sshd process from running into limits and gives
the tests a little more headroom as the sshd process won't count
against the tests' limits.
Change-Id: I4a047a2d018f80a64d5f0495f5c57d125fe1119f