Project migration using CAM tool fails while copying images due to "manifest unknown blob" error

Issue

• Application migration from RHOCP v3.x to v4.x fails to create the InitialBackup with the following messages:

Error copying image: Error writing manifest: Error uploading manifest latest to <registry-svc>:5000/<project>/<image-name>: errors:\nmanifest blob unknown: blob unknown to registry\nmanifest blob unknown: blob unknown to registry\n" backup=openshift-migration/migmigration-xxxx-xxxx cmd=/plugins/velero-plugins logSource="/go/src/github.com/fusor/openshift-migration-plugin/velero-plugins/migimagestream/backup.go:84" pluginName=velero-plugins
time="<TZ>" level=info msg="1 errors encountered backup up item" backup=openshift-migration/migmigration-xxxx-xxxx group=image.openshift.io/v1 logSource="pkg/backup/resource_backupper.go:284" name=<image-name> namespace=<project-name> resource=imagestreams