vdsm.spec: own metadata supervdsm mom logs

/var/log/vdsm/metadata.log /var/log/vdsm/supervdsm.log
/var/log/vdsm/mom.log should be owned by VDSM.

Additionaly, now are now creating with touch those files
(and vdsm.log) during the vdsm rpm install.

Change-Id: I2776b8518930393b281a1885268813f8d4d7c85b
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1055153
Signed-off-by: Douglas Schilling Landgraf <dougsland@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/23754
Reviewed-by: Dan Kenigsberg <danken@redhat.com>