Since old-style nic config files can no longer be used in Queens
or Rocky (the format changed in Ocata), add a check in yaml-validate
to detect that old-style files are in use and list conversion script
that can be used.
Made some changes to the script to ask before overwriting the nic
config file and save a datestamped copy as backup. In addition,
the script now takes an optional parameter to define location
of run-os-net-config.sh.
Change-Id: Ic56c48fa35ab2f4c1762c0e370be03fbf2e7671c
Closes-Bug: 1753812