fix: emit standard OTel cloud.resource_id for Agent Engine telemetry

The agent-engine branch of get_gcp_resource() emitted the resource id under
a non-standard "cloud.resource.id" key, so the Agent Engine dashboard's
cloud.resource_id filter matched no rows and every panel read 0. Use the
OTel CLOUD_RESOURCE_ID constant ("cloud.resource_id").

Close #6247

Co-authored-by: George Weale <gweale@google.com>
PiperOrigin-RevId: 943528352

Author: GWeale

src/google/adk/telemetry/google_cloud.py

@@ -43,6 +43,13 @@
 
 logger = logging.getLogger("google_adk." + __name__)
 
+try:
+  from opentelemetry.semconv._incubating.attributes.cloud_attributes import CLOUD_RESOURCE_ID
+except ImportError:
+  # cloud.resource_id only lives in the private _incubating package; fall back
+  # to the literal key the Agent Engine dashboard filters on if that path moves.
+  CLOUD_RESOURCE_ID = "cloud.resource_id"
+
 _GCP_LOG_NAME_ENV_VARIABLE_NAME = "GOOGLE_CLOUD_DEFAULT_LOG_NAME"
 _DEFAULT_LOG_NAME = "adk-otel"
 
@@ -246,7 +253,7 @@ def get_gcp_resource(project_id: Optional[str] = None) -> Resource:
       ),
   }
   if cloud_resource_id is not None:
-    resource_attributes["cloud.resource.id"] = cloud_resource_id
+    resource_attributes[CLOUD_RESOURCE_ID] = cloud_resource_id
 
   if agent_engine_id:
     resource = Resource.create(attributes=resource_attributes).merge(

tests/unittests/telemetry/test_google_cloud.py

@@ -113,6 +113,25 @@ def test_get_gcp_resource(
   )
 
 
+def test_get_gcp_resource_sets_standard_cloud_resource_id(
+    monkeypatch: pytest.MonkeyPatch,
+):
+  # Arrange.
+  monkeypatch.setenv("GOOGLE_CLOUD_AGENT_ENGINE_ID", "1234567890")
+  monkeypatch.setenv("GOOGLE_CLOUD_LOCATION", "us-central1")
+
+  # Act.
+  otel_resource = get_gcp_resource("my-project")
+
+  # Assert.
+  # The Agent Engine dashboard filters on the OTel-standard key.
+  assert otel_resource.attributes.get("cloud.resource_id") == (
+      "//aiplatform.googleapis.com/projects/my-project"
+      "/locations/us-central1/reasoningEngines/1234567890"
+  )
+  assert "cloud.resource.id" not in otel_resource.attributes
+
+
 @mock.patch.object(mtls, "should_use_client_cert", autospec=True)
 def test_use_client_cert_effective_from_mtls(mock_should_use):
   mock_should_use.return_value = True