Fix 'block_store' aliases define error
Fix 'block_store' aliases define error

This patch fix volume aliases error, the service type use
'block-storage', but aliases define use 'block_storage'.
So, Can't use 'block_store' finish list volumes.

Change-Id: I003f7064c13dc907833c2a1e66cc11a823d47be6
Closes-Bug: #1757032

stackforge/python-openstacksdk,openstack/python-openstacksdk,stackforge/python-openstacksdk,dtroyer/python-openstacksdk,openstack/python-openstacksdk,dtroyer/python-openstacksdk