Fix HTTPRoute status to match API standard

[solmonk]

What type of PR is this?

bug

Which issue does this PR fix:

This will make httproutes to be properly recognized as "accepted", in external integrations such as ExternalDNS.

What does this PR do / Why do we need it:

This is required if we go ExternalDNS integration path, and will also help later as we support more addons.

If an issue # is not available please add repro steps and logs from aws-gateway-controller showing the issue:

Testing done on this change:
In a manual test setting on kubectl get httproute byoc-parking -o yaml:

apiVersion: gateway.networking.k8s.io/v1beta1
kind: HTTPRoute
metadata:
  annotations:
    application-networking.k8s.aws/lattice-assigned-domain-name: byoc-parking-default-04dbcef00d405a0fd.7d67968.vpc-lattice-svcs.us-west-2.on.aws
    kubectl.kubernetes.io/last-applied-configuration: |
      {"apiVersion":"gateway.networking.k8s.io/v1beta1","kind":"HTTPRoute","metadata":{"annotations":{},"name":"byoc-parking","namespace":"default"},"spec":{"hostnames":["parking.my-test.com"],"parentRefs":[{"name":"my-hotel","sectionName":"http"}],"rules":[{"backendRefs":[{"kind":"Service","name":"parking-ver2","port":8090}]}]}}
  creationTimestamp: "2023-05-09T22:16:14Z"
  finalizers:
  - httproute.k8s.aws/resources
  generation: 1
  name: byoc-parking
  namespace: default
  resourceVersion: "1847234"
  uid: 32997b22-4b5e-4195-8373-92ea8ec8b6ab
spec:
  hostnames:
  - parking.my-test.com
  parentRefs:
  - group: gateway.networking.k8s.io
    kind: Gateway
    name: my-hotel
    sectionName: http
  rules:
  - backendRefs:
    - group: ""
      kind: Service
      name: parking-ver2
      port: 8090
      weight: 1
    matches:
    - path:
        type: PathPrefix
        value: /
status:
  parents:
  - conditions:
    - lastTransitionTime: "2023-05-09T22:16:39Z"
      message: 'DNS Name: byoc-parking-default-04dbcef00d405a0fd.7d67968.vpc-lattice-svcs.us-west-2.on.aws'
      reason: Accepted
      status: "True"
      type: Accepted
    controllerName: application-networking.k8s.aws/gateway-api-controller
    parentRef:
      group: gateway.networking.k8s.io
      kind: Gateway
      name: my-hotel

Automation added to e2e:

Will this PR introduce any new dependencies?:
no

Will this break upgrades or downgrades. Has updating a running cluster been tested?:

Does this PR introduce any user-facing change?:

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[coveralls]

Pull Request Test Coverage Report for Build 4940827311

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 31.941%

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Totals
Change from base Build 4877197379:	0.0%
Covered Lines:	3196
Relevant Lines:	10006

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💛 - Coveralls

[liwenwu-amazon]

Can you re-run gateway API conformance test for this change?

[solmonk]

Conformance test result was the same as the report - all previously passing tests were also passing.

[liwenwu-amazon]

can u also make sure existing e2e test still passing? thanks

[solmonk]

can confirm e2e test is still passing.