[ShankBot] [bug 1784290] Packages copied to the wrong component

[brad.figg at canonical.com]

The following packages ended up in the wrong component in the -proposed pocket:

linux-signed-gcp 4.15.0-1016.17 - is in universe instead of main
linux-image-4.15.0-1016-gcp 4.15.0-1016.17 - is in universe instead of main
linux-image-4.15.0-1016-gcp-dbgsym 4.15.0-1016.17 - is in universe instead of main