Add the miss 'Snapshot' option for "Volume Source"
Add the miss 'Snapshot' option for "Volume Source"

"Volume Source" on "Create Volume" dialog miss "Snapshot" option。

Change-Id: I7be204a2d2ff74a42972621ddb598c7d6f4caf47
Closes-Bug: #1588365

AlekhyaMallina-Vedams/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals,openstack/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals,openstack/openstack-manuals,AlekhyaMallina-Vedams/openstack-manuals