fix span name when using the OpenTelemetry tracing provider

[zirain]

Please provide a description of this PR:

fix: #51039

related to envoyproxy/envoy#34062 and envoyproxy/envoy#34063

[istio-policy-bot]

🤔 🐛 You appear to be fixing a bug in Go code, yet your PR doesn't include updates to any test files. Did you forget to add a test?

Courtesy of your friendly test nag.

[howardjohn]

can you help understand this change? was it intentional? is it in need of a release note? etc

[zirain]

before:

[
    {
        "traceId": "8f52b66b50bb0ee219bfeacbd55ec801",
        "parentId": "00919a47cbbe1e80",
        "id": "8dd6684f51ff3ab9",
        "kind": "SERVER",
        "name": "ingress",
        "timestamp": 1715794113386340,
        "duration": 19624,
        "localEndpoint": {
            "serviceName": "httpbin.default"
        },
        "tags": {
            "component": "proxy",
            "downstream_cluster": "-",
            "guid:x-request-id": "d004fc12-b5bd-9531-a625-324728634a0a",
            "http.method": "GET",
            "http.protocol": "HTTP/1.1",
            "http.status_code": "200",
            "http.url": "http://httpbin:8000/get",
            "istio.canonical_revision": "v1",
            "istio.canonical_service": "httpbin",
            "istio.cluster_id": "Kubernetes",
            "istio.mesh_id": "cluster.local",
            "istio.namespace": "default",
            "node_id": "sidecar~10.244.0.13~httpbin-86b8ffc5ff-6l4k5.default~default.svc.cluster.local",
            "peer.address": "10.244.0.12",
            "request_size": "0",
            "response_flags": "-",
            "response_size": "533",
            "upstream_cluster": "inbound|8080||",
            "upstream_cluster.name": "inbound|8080||",
            "user_agent": "curl/8.7.1",
            "zone": ""
        }
    },
    {
        "traceId": "8f52b66b50bb0ee219bfeacbd55ec801",
        "id": "00919a47cbbe1e80",
        "kind": "CLIENT",
        "name": "egress httpbin:8000",
        "timestamp": 1715794113377458,
        "duration": 33593,
        "localEndpoint": {
            "serviceName": "sleep.default"
        },
        "tags": {
            "component": "proxy",
            "downstream_cluster": "-",
            "guid:x-request-id": "d004fc12-b5bd-9531-a625-324728634a0a",
            "http.method": "GET",
            "http.protocol": "HTTP/1.1",
            "http.status_code": "200",
            "http.url": "http://httpbin:8000/get",
            "istio.canonical_revision": "latest",
            "istio.canonical_service": "sleep",
            "istio.cluster_id": "Kubernetes",
            "istio.mesh_id": "cluster.local",
            "istio.namespace": "default",
            "node_id": "sidecar~10.244.0.12~sleep-7656cf8794-qsff2.default~default.svc.cluster.local",
            "peer.address": "10.244.0.12",
            "request_size": "0",
            "response_flags": "-",
            "response_size": "533",
            "upstream_cluster": "outbound|8000||httpbin.default.svc.cluster.local",
            "upstream_cluster.name": "outbound|8000||httpbin.default.svc.cluster.local",
            "user_agent": "curl/8.7.1",
            "zone": ""
        }
    }
]

after:

[
    {
        "traceId": "e23e9c943172432e68b6f4f4fb508deb",
        "parentId": "23d0cd36428d63ea",
        "id": "bda2bc8bff945277",
        "kind": "SERVER",
        "name": "httpbin.default.svc.cluster.local:8000/*",
        "timestamp": 1715794389528590,
        "duration": 3910,
        "localEndpoint": {
            "serviceName": "httpbin.default"
        },
        "tags": {
            "component": "proxy",
            "downstream_cluster": "-",
            "guid:x-request-id": "662bcff8-6d45-9c65-8a0a-72e4961fb5af",
            "http.method": "GET",
            "http.protocol": "HTTP/1.1",
            "http.status_code": "200",
            "http.url": "http://httpbin:8000/get",
            "istio.canonical_revision": "v1",
            "istio.canonical_service": "httpbin",
            "istio.cluster_id": "Kubernetes",
            "istio.mesh_id": "cluster.local",
            "istio.namespace": "default",
            "node_id": "sidecar~10.244.0.38~httpbin-86b8ffc5ff-gcbq2.default~default.svc.cluster.local",
            "peer.address": "10.244.0.39",
            "request_size": "0",
            "response_flags": "-",
            "response_size": "533",
            "upstream_cluster": "inbound|8080||",
            "upstream_cluster.name": "inbound|8080||",
            "user_agent": "curl/8.7.1",
            "zone": ""
        }
    },
    {
        "traceId": "e23e9c943172432e68b6f4f4fb508deb",
        "id": "23d0cd36428d63ea",
        "kind": "CLIENT",
        "name": "httpbin.default.svc.cluster.local:8000/*",
        "timestamp": 1715794389521838,
        "duration": 14410,
        "localEndpoint": {
            "serviceName": "sleep.default"
        },
        "tags": {
            "component": "proxy",
            "downstream_cluster": "-",
            "guid:x-request-id": "662bcff8-6d45-9c65-8a0a-72e4961fb5af",
            "http.method": "GET",
            "http.protocol": "HTTP/1.1",
            "http.status_code": "200",
            "http.url": "http://httpbin:8000/get",
            "istio.canonical_revision": "latest",
            "istio.canonical_service": "sleep",
            "istio.cluster_id": "Kubernetes",
            "istio.mesh_id": "cluster.local",
            "istio.namespace": "default",
            "node_id": "sidecar~10.244.0.39~sleep-7656cf8794-nvkcr.default~default.svc.cluster.local",
            "peer.address": "10.244.0.39",
            "request_size": "0",
            "response_flags": "-",
            "response_size": "533",
            "upstream_cluster": "outbound|8000||httpbin.default.svc.cluster.local",
            "upstream_cluster.name": "outbound|8000||httpbin.default.svc.cluster.local",
            "user_agent": "curl/8.7.1",
            "zone": ""
        }
    }
]

[zirain]

can you help understand this change? was it intentional? is it in need of a release note? etc

related to envoyproxy/envoy#34063, it worked as expected.