Automatic merge from submit-queue
support for mounting local-ssds on GCI
This change adds support for mounting local ssds on GCI.
It updates the previous container-vm behavior as well to
match that for GCI nodes by mounting the local-ssds under
the same path (/mnt/disks/ssdN).
@vulpecula @roberthbailey @andyzheng0831 @kubernetes/goog-image