Instead of including Cuttlefish in the core LAVA rootfs, make it an optional LAVA overlay. This reduces the size of the core rootfs and keeps Cuttlefish cached when the container is rebuilt, leading to faster deploys. Signed-off-by: Valentine Burley <valentine.burley@collabora.com> Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/35522>