common-ostree: Explicitly list lvm2

Surprisingly in comps, it's just part of the anaconda group,
and so it ends up on workstation systems indirectly because
anaconda is part of the livecd.

For Fedora Atomic Host, we list it explicitly.

It turns out that when we dropped `docker/atomic`, nothing else
was pulling in `lvm2`.

fedora-common-ostree.json

@@ -11,6 +11,7 @@
         "flatpak",
         "flatpak-builder",
         "git-core",
+        "lvm2",
         "podman",
         "rpm-ostree",
         "skopeo",