Fix #8398 - volumes copying data unexpectedly

Prior to the volumes re-factor, data was not being copied on
volumes-from or host-mounted volumes.
After the re-factor, data was being copied for volumes-from.
This reverts this unintentional change in behavior.

Signed-off-by: Brian Goff <cpuguy83@gmail.com>
Merge pull request #8417 from cpuguy83/8398_fix_automatic_data_copy_for_volumesfrom

volumes copying data unexpectedly