Move wait_for_qos_operations into base volume test

wait_for_qos_operations() is just a wrapper method, and a service
client module is not a good place to keep the method as a stable
interface.
This patch moves wait_for_qos_operations into base volume test
module.

Partially implements blueprint consistent-service-method-names

Change-Id: Icb049981630142b68a7473c2e04979a6ae3942a0
3 files changed