Don't use lvmetad

lvmetad has a problem in the current package, and vdsm disables it
anyway. Disable it for now, but check on it in the future when the
upstream fix lands in a package.

Change-Id: Ie111f462d15bde004506638e3d70943e3dd9daba
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1147217
Signed-off-by: Ryan Barry <rbarry@redhat.com>