There are Quantum plugins that do not require the use of an agent.
This patch relaxes the constraint in quantum-adv-test.sh by adding
the ability to customize the logic that verifies whether the test
can run or not, depending on the Quantum plugin of your choice.
Fixes bug #1177904
Change-Id: I6e2c17f43d9e1475b2eb175cceb5107a83f9aa74