If there is a failed resize that also failed the cleanup
process performed by _cleanup_remote_migration() the retry
of the resize will fail because it cannot rename the current
instances directory to _resize.
This renames the _cleanup_failed_migration() that does the
same logic we want to _cleanup_failed_instance_base() and
uses it for both migration and resize cleanup of directory.
It then simply calls _cleanup_failed_instances_base() with
the resize dir path before trying a resize.
Closes-Bug: 1960230
Change-Id: I7412b16be310632da59a6139df9f0913281b5d77
9111b99f73