[stable/queens-only][ci] Enable LVM job

The LVM job in the check queue was set to non-voting
and the gate job was disabled due to bug 1833696 in
DevStack. It's now been fixed [1]. So revert changes
to this job.

[1] https://review.opendev.org/#/c/669872/
Closes-Bug: #1833696

Change-Id: I3ce5cbee3ab82804871d7363eea53f319d96fce1

.zuul.yaml

@@ -26,11 +26,7 @@
         - manila-tempest-minimal-dsvm-cephfs-nfs-centos-7:
             voting: false
         - manila-tempest-minimal-dsvm-dummy
-# TODO(gouthamr): make lvm job voting again
-# after https://bugs.launchpad.net/devstack/+bug/1833696
-# is fixed.
-        - manila-tempest-minimal-dsvm-lvm-centos-7:
-            voting: false
+        - manila-tempest-minimal-dsvm-lvm-centos-7
         - grenade-dsvm-manila:
             voting: false
         - rally-dsvm-manila-multibackend:
@@ -46,10 +42,7 @@
       jobs:
         - manila-tox-genconfig
         - manila-tempest-minimal-dsvm-dummy
-# TODO(gouthamr): make lvm job voting again
-# after https://bugs.launchpad.net/devstack/+bug/1833696
-# is fixed.
-#       - manila-tempest-minimal-dsvm-lvm-centos-7
+        - manila-tempest-minimal-dsvm-lvm-centos-7
     experimental:
       jobs:
         - manila-tempest-dsvm-glusterfs-nfs