Add variable to set volume service version on tempest

Tempest is going to test volume v3 APIs as default
in gate and running a separate job to run tests on v2 APIs.

To give this ability, this commit provide a var to tell
which API version need to be tested and accordingly it
configure the catalog_type and microversion setting on tempest.

Change-Id: I531f3b32e81ac5d282461597ca286c09429cb143
Needed-By: I0c9193501eb9eaa25eb5f0786bb72eb7855099fb
1 file changed