Many of the templates use 600, remove unnecessary permission
on these templates to bring them in line with the others.

Change-Id: I30fe1b3822b9c7bb6ab98729fc519dc1d603db27

Add a nova-ssh container to handle the `nova migrate` and
`nova resize` case, in which the nova will use ssh to copy
files between machines.

Change-Id: Ie6675943f3aeabfbba8589d308d55b9c89d732db
Closes-Bug: #1562141