When two listeners are added with the same name, listener is not closed

[dawid-nowak]

Steps to reproduce:

1. Via xDS add a listener with name "listener1" routing to a cluster named "cluster_one" with endpoint 127.0.0.1:10000
2. Make some calls and ensure that the responses are valid.
3. Via xDS add a listener with name "listener1" routing to a different cluster for example "cluster_two" with endpoint 127.0.0.1:20000
4. Make some calls...

I think we will see a mixture of responses coming back from both endpoints but we should only see responses from 127.0.0.1:20000

Potential, fix is to add stop_listener around line 135 in listeners_manager

[Eeshu-Yadav]

/assign

[hzxuzhonghu]

What is the expected logic for this? As we are storing the listener by name, what if the address is duplicated for two different listeners.