Added ability to not run share group snapshot tests

Also added one more test for share group usages in order to have ability
to test usages when snapshots are not supported.

Change-Id: Ied4915c8110f90bf37fabe0b9eb575db2291a230
Related-Prod: https://mirantis.jira.com/browse/PRODX-48556
(cherry picked from commit a857dc55df61f6a4c61de453c8fdc7a3b6a0186b)
5 files changed