A previous commit made the Windows containerd/platforms.Default stricter
by requiring the OS Version to have a similar OS Version as the node's OS Version.
However, tar images (from docker save) do not have any OS Version information,
causing the containerd/import.Import's images.FilterPlatforms to filter out the image
entirely, which means that the images.SetChildrenLabels doesn't get to label
any children, which in turn will cause the Garbage Collector to remove content
related to the image.
This sets a default platform for the imported image if it's a Windows image which
doesn't have any OSVersion information, or if there's no platform information at
all.
Signed-off-by: Claudiu Belu <cbelu@cloudbasesolutions.com>
6b0b64a51a