roachprod: gce arm64 and local ssd machine types

Prior to this patch, the supported machine families in GCE was partial.
Only t2a was considered ARM64, and local SSD was only supported for n1
and n2 families.

This patch brings machine family parsing and capabilities deduction for
all machine types available in GCE as of today.

Epic: none
Release note: None

Author: golgeek