We want to enable support for multiple packages for DLC since this is supported by update engine and Omaha. Currently we only allow a single partition (dlc.img), but this is limiting since all files must be placed in a single image.

If we modify the current DLC implementation to allow for multiple partitions, we must account for updates in which partitions are added or removed, since dlcservice will not know what to do with these new partitions until after we chroot into the updated platform.