Mock OVSBrdge.clear_minimum_bandwidth_qos in fullstack tests

This function will not be executed when the OVS agent is started,
in order to keep QoS and Queue registers in OVS BD created by other
tests.

Change-Id: I054510403a4f46544ff78ee2f6babb1247726553
Closes-Bug: #1819125
(cherry picked from commit 531fdc336b)

neutron/tests/fullstack/agents/ovs_agent.py

@@ -15,8 +15,10 @@
 
 import sys
 
+import mock
 from oslo_config import cfg
 
+from neutron.agent.common import ovs_lib
 from neutron.services.trunk.drivers.openvswitch.agent \
     import driver as trunk_driver
 from neutron.tests.common.agents import ovs_agent
@@ -42,7 +44,8 @@ def main():
     # ovs-vswitchd processes for each test will be isolated in separate
     # namespace
     monkeypatch_init_handler()
-    ovs_agent.main()
+    with mock.patch.object(ovs_lib.OVSBridge, 'clear_minimum_bandwidth_qos'):
+        ovs_agent.main()
 
 
 if __name__ == "__main__":

neutron/tests/fullstack/test_qos.py

@@ -23,7 +23,6 @@ import testscenarios
 from neutron.agent.common import ovs_lib
 from neutron.agent.linux import tc_lib
 from neutron.common import utils
-from neutron.tests import base as tests_base
 from neutron.tests.common.agents import l2_extensions
 from neutron.tests.fullstack import base
 from neutron.tests.fullstack.resources import environment
@@ -630,7 +629,6 @@ class _TestMinBwQoS(BaseQoSRuleTestCase):
         rule['qos_policy_id'] = qos_policy_id
         qos_policy['rules'].append(rule)
 
-    @tests_base.unstable_test('bug 1819125')
     def test_min_bw_qos_policy_rule_lifecycle(self):
         new_limit = MIN_BANDWIDTH - 100
 
@@ -680,7 +678,6 @@ class TestMinBwQoSOvs(_TestMinBwQoS, base.BaseFullStackTestCase):
             self.fail('"%s" direction not implemented'
                       % constants.INGRESS_DIRECTION)
 
-    @tests_base.unstable_test('bug 1819125')
     def test_bw_limit_qos_port_removed(self):
         """Test if rate limit config is properly removed when whole port is
         removed.