Rectify volumes tests

* pass updated stack parameters directly to keep the original value
* volume property of display_description ain't available
  in cinder api version 2+

Closes-Bug: PRODX-1111
Change-Id: I346b4da7d002e86f39280ef6caf141a18b0404e3
(cherry picked from commit d86710c69571058702c0fc86063b1b2632030cf8)
2 files changed