Commit 55fc718f98 moved a QoS data
plane test from Neutron Gateway tests to the Neutron API tests.
This was probably done because the Neutron API charm gate was
doing end to end tests for all deployment topologies.
On the back of splitting out the data plane tests from Neutron API
gate to the respective data plane charms we need to move this
test back where it belongs.
Apparantly the Neutron Open vSwitch test class have its own
variant of this test already that will be executed by the
neutron-openvswitch charm gate.
82928825fd