Add outlier detection failure matcher

[Samarth6840]

What this PR does

Adds outlier_detection_http_error_codes to OutlierDetection in DestinationRule,
allowing users to specify additional HTTP status codes (beyond the default 5xx) to
be treated as outlier detection failures.

Maps to Envoy's new outlier_detection.failure_matcher in HttpProtocolOptions
(envoyproxy/envoy#39947).

Follows the same simplification pattern as consecutiveGatewayErrors /
consecutive5xxErrors (#1189) — a plain repeated field rather than exposing
Envoy's raw MatchPredicate, consistent with Istio's existing approach (e.g.
VirtualService's retryOn).

Related

Implements the API portion of istio/istio#60828

Next steps

Wiring into istio/istio's cluster_traffic_policy.go (HttpProtocolOptions
section) will follow in a separate PR.

[istio-policy-bot]

😊 Welcome @Samarth6840! This is either your first contribution to the Istio api repo, or it's been
a while since you've been here.

You can learn more about the Istio working groups, Code of Conduct, and contribution guidelines
by referring to Contributing to Istio.

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[linux-foundation-easycla]

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• ✅ login: Samarth6840 / name: Samarth Joshi (0ab9dbe, 93a41ab)

[istio-testing]

Hi @Samarth6840. Thanks for your PR.

I'm waiting for a istio member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work.

Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Details

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[ramaraochavali]

/ok-to-test

[istio-testing]

@Samarth6840: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
release-notes_api	1d458eb	link	false	/test release-notes

Details

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository. I understand the commands that are listed here.