9ce329f1c6
https://build.spring.io/browse/INT-SI50X-20
Looks like 5 seconds is not enough to wait for the test completion,
especially on CI server
* Refactor `PollingConsumerEndpointTests` to use `OnlyOnceTrigger`
from the test-support module instead of local `Trigger` implementation
* Increase timeout for latch in the `OnlyOnceTrigger` to 10 seconds
**Cherry-pick to 5.0.x**
(cherry picked from commit a65d05c)