Fix the bug where proper port filtering based on the destination
is not applied.

consider the following dst pod with the LRP policy

  containers:
  - image: nginx:latest
    imagePullPolicy: Always
    name: nginx
    ports:
    - containerPort: 80
      name: http
      protocol: TCP
    - containerPort: 443
      name: https
      protocol: TCP
    - containerPort: 8080
      name: http-alt
      protocol: TCP
    - containerPort: 9090
      name: metrics
      protocol: TCP
    - containerPort: 3000
      name: app
      protocol: TCP
-----
 apiVersion: cilium.io/v2
 kind: CiliumLocalRedirectPolicy
 metadata:
   annotations:
   name: lrp-addr
   namespace: default
 spec:
   redirectBackend:
     localEndpointSelector:
       matchLabels:
         app: nginx-test
     toPorts:
     - port: "80"
       protocol: TCP
   redirectFrontend:
     addressMatcher:
       ip: 169.254.169.254
       toPorts:
       - port: "8080"
         protocol: TCP
   skipRedirectFromBackend: false

Without port filtering, all possible ports will be allowed, even if the
destination port is specifically configured as 80:

12   169.254.169.254:8080/TCP   LocalRedirect   1 => 10.244.1.86:80/TCP (active)
                                                2 => 10.244.1.86:443/TCP (active)
                                                3 => 10.244.1.86:3000/TCP (active)
                                                4 => 10.244.1.86:8080/TCP (active)
                                                5 => 10.244.1.86:9090/TCP (active)

With this patch, the correct port filtering is applied, and we get the
expected behavior:

14   169.254.169.254:8080/TCP   LocalRedirect   1 => 10.244.1.86:80/TCP (active)

Signed-off-by: Liyi Huang <liyi.huang@isovalent.com>

Based on our doc, we have ports specified in toPorts under redirectBackend
exist in the backend pod spec. I can see the unit test is using lrp to
forward to 8080 but the pod is listening port 80.

I ran into this issue when implementing filter the backend based on the port.
That's how I find this issue.

Signed-off-by: Liyi Huang <liyi.huang@isovalent.com>