local storage is not enabled on the zone

Signed-off-by: Prasanna Santhanam <tsp@apache.org>
(cherry picked from commit d8e5b8907bc97ca58017c0aedff03658a63f1955)
CLOUDSTACK-4144: Add free vlan to shared network in TestVMLifeCycleSharedNwVPC

Shared network has to have specifyVlan = True. So changed it to True
and aded a function to get free vlan.

Signed-off-by: Prasanna Santhanam <tsp@apache.org>
(cherry picked from commit 9ff40829a9787df6d89fea3c41dd112554533be7)