[FT] Increate the bridge creation event timeout

This event is used in ``BridgeMonitorTestCase.test_create_bridges``.

Related-Bug: #2114909
Signed-off-by: Rodolfo Alonso Hernandez <[email protected]>
Change-Id: I36a32c7b6eb44aa2ac315b1e51d54ee662c1d189
(cherry picked from commit cc70581)

Author: ralonsoh

neutron/tests/functional/agent/ovsdb/native/test_connection.py

@@ -25,7 +25,7 @@ class WaitForBridgesEvent(event.RowEvent):
     event_name = 'WaitForBridgesEvent'
     ONETIME = True
 
-    def __init__(self, bridges, timeout=5):
+    def __init__(self, bridges, timeout=20):
         self.bridges_not_seen = set(bridges)
         self.timeout = timeout
         self.event = threading.Event()