Support DD_METRICS_OTEL_ENABLED feature-flag (#10685)

Support DD_METRICS_OTEL_ENABLED feature-flag

Merge branch 'master' into mcculls/otel-metrics-enabled-flag

Co-authored-by: stuart.mcculloch <stuart.mcculloch@datadoghq.com>

Author: mcculls

dd-java-agent/instrumentation/opentelemetry/opentelemetry-1.47/src/main/java/datadog/trace/instrumentation/opentelemetry147/OpenTelemetryMetricsInstrumentation.java

@@ -10,6 +10,7 @@
 import datadog.opentelemetry.shim.metrics.OtelMeterProvider;
 import datadog.trace.agent.tooling.Instrumenter;
 import datadog.trace.agent.tooling.InstrumenterModule;
+import datadog.trace.api.InstrumenterConfig;
 import io.opentelemetry.api.metrics.MeterProvider;
 import net.bytebuddy.asm.Advice;
 import net.bytebuddy.description.type.TypeDescription;
@@ -31,8 +32,7 @@ public OpenTelemetryMetricsInstrumentation() {
 
   @Override
   protected boolean defaultEnabled() {
-    // TODO: return InstrumenterConfig.get().isMetricsOtelEnabled(); when fully implemented
-    return false;
+    return InstrumenterConfig.get().isMetricsOtelEnabled();
   }
 
   @Override

dd-java-agent/instrumentation/opentelemetry/opentelemetry-1.47/src/test/groovy/OpenTelemetry147ActivationTest.groovy

@@ -43,8 +43,7 @@ class OpenTelemetry147ActivationByOtelRfcNameForkedTest extends OpenTelemetry147
 
   @Override
   boolean shouldBeInjected() {
-    // TODO: true when OTel metrics fully implemented
-    return false
+    return true
   }
 }
 

dd-java-agent/instrumentation/opentelemetry/opentelemetry-1.47/src/test/groovy/opentelemetry147/metrics/MetricsTest.groovy

@@ -24,7 +24,7 @@ class MetricsTest extends InstrumentationSpecification {
   void configurePreAgent() {
     super.configurePreAgent()
 
-    injectSysConfig("dd.integration.opentelemetry-metrics.enabled", "true")
+    injectSysConfig("dd.metrics.otel.enabled", "true")
   }
 
   @Shared