Add description to policies in assisted_volume_snapshots.py
Add description to policies in assisted_volume_snapshots.py

blueprint policy-doc

Change-Id: I73c29c5e046d871a2a38ec618df3ffd742b3070a

vmturbo/nova,rajalokan/nova,openstack/nova,mikalstill/nova,vmturbo/nova,Juniper/nova,Juniper/nova,gooddata/openstack-nova,rahulunair/nova,klmitch/nova,phenoxim/nova,gooddata/openstack-nova,openstack/nova,rahulunair/nova,openstack/nova,klmitch/nova,rajalokan/nova,phenoxim/nova,mahak/nova,gooddata/openstack-nova,rajalokan/nova,klmitch/nova,vmturbo/nova,jianghuaw/nova,klmitch/nova,rahulunair/nova,mahak/nova,Juniper/nova,mahak/nova,jianghuaw/nova,mikalstill/nova,jianghuaw/nova,rajalokan/nova,jianghuaw/nova,mikalstill/nova,Juniper/nova,vmturbo/nova,gooddata/openstack-nova