Add otel metrics enable config but doesn't use it

Author: cecile75

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

@@ -25,6 +25,7 @@ public OpenTelemetryInstrumentation() {
 
   @Override
   protected boolean defaultEnabled() {
+    // Not activated yet to prevent NPE
     // return InstrumenterConfig.get().isMetricsOtelEnabled();
     return false;
   }

internal-api/src/main/java/datadog/trace/api/InstrumenterConfig.java

@@ -7,6 +7,7 @@
 import static datadog.trace.api.ConfigDefaults.DEFAULT_INTEGRATIONS_ENABLED;
 import static datadog.trace.api.ConfigDefaults.DEFAULT_LLM_OBS_ENABLED;
 import static datadog.trace.api.ConfigDefaults.DEFAULT_MEASURE_METHODS;
+import static datadog.trace.api.ConfigDefaults.DEFAULT_METRICS_OTEL_ENABLED;
 import static datadog.trace.api.ConfigDefaults.DEFAULT_RESOLVER_RESET_INTERVAL;
 import static datadog.trace.api.ConfigDefaults.DEFAULT_RUM_ENABLED;
 import static datadog.trace.api.ConfigDefaults.DEFAULT_RUNTIME_CONTEXT_FIELD_INJECTION;
@@ -29,6 +30,7 @@
 import static datadog.trace.api.config.GeneralConfig.TRIAGE_REPORT_TRIGGER;
 import static datadog.trace.api.config.IastConfig.IAST_ENABLED;
 import static datadog.trace.api.config.LlmObsConfig.LLMOBS_ENABLED;
+import static datadog.trace.api.config.OtlpConfig.METRICS_OTEL_ENABLED;
 import static datadog.trace.api.config.ProfilingConfig.PROFILING_DIRECT_ALLOCATION_ENABLED;
 import static datadog.trace.api.config.ProfilingConfig.PROFILING_DIRECT_ALLOCATION_ENABLED_DEFAULT;
 import static datadog.trace.api.config.ProfilingConfig.PROFILING_ENABLED;
@@ -91,9 +93,6 @@
 import java.util.Map;
 import java.util.Set;
 
-// import static datadog.trace.api.config.OtelConfig.METRICS_OTEL_ENABLED;
-// import static datadog.trace.api.ConfigDefaults.DEFAULT_METRICS_OTEL_ENABLED;
-
 /**
  * This config is needed before instrumentation is applied
  *
@@ -119,7 +118,7 @@ public class InstrumenterConfig {
   private final boolean codeOriginEnabled;
   private final boolean traceEnabled;
   private final boolean traceOtelEnabled;
-  // private final boolean metricsOtelEnabled;
+  private final boolean metricsOtelEnabled;
   private final ProfilingEnablement profilingEnabled;
   private final boolean ciVisibilityEnabled;
   private final ProductActivation appSecActivation;
@@ -213,8 +212,8 @@ private InstrumenterConfig() {
             CODE_ORIGIN_FOR_SPANS_ENABLED, DEFAULT_CODE_ORIGIN_FOR_SPANS_ENABLED);
     traceEnabled = configProvider.getBoolean(TRACE_ENABLED, DEFAULT_TRACE_ENABLED);
     traceOtelEnabled = configProvider.getBoolean(TRACE_OTEL_ENABLED, DEFAULT_TRACE_OTEL_ENABLED);
-    // metricsOtelEnabled = configProvider.getBoolean(METRICS_OTEL_ENABLED,
-    // DEFAULT_METRICS_OTEL_ENABLED);
+    metricsOtelEnabled =
+        configProvider.getBoolean(METRICS_OTEL_ENABLED, DEFAULT_METRICS_OTEL_ENABLED);
 
     profilingEnabled =
         ProfilingEnablement.of(
@@ -379,9 +378,9 @@ public boolean isTraceOtelEnabled() {
     return traceOtelEnabled;
   }
 
-  // public boolean isMetricsOtelEnabled() {
-  //   return metricsOtelEnabled;
-  // }
+  public boolean isMetricsOtelEnabled() {
+    return metricsOtelEnabled;
+  }
 
   public boolean isProfilingEnabled() {
     return profilingEnabled.isActive();
@@ -636,8 +635,8 @@ public String toString() {
         + traceEnabled
         + ", traceOtelEnabled="
         + traceOtelEnabled
-        // + ", metricsOtelEnabled="
-        // + metricsOtelEnabled
+        + ", metricsOtelEnabled="
+        + metricsOtelEnabled
         + ", profilingEnabled="
         + profilingEnabled
         + ", ciVisibilityEnabled="