check for exporter env vars and pass to metricdatamapper

Author: harsimar

agent/agent-tooling/src/main/java/com/microsoft/applicationinsights/agent/internal/init/SecondEntryPoint.java

@@ -69,6 +69,7 @@
 import io.opentelemetry.sdk.trace.SdkTracerProviderBuilder;
 import io.opentelemetry.sdk.trace.export.SpanExporter;
 import io.opentelemetry.sdk.trace.samplers.SamplingDecision;
+import io.opentelemetry.sdk.autoconfigure.spi.ConfigProperties;
 import java.io.File;
 import java.util.ArrayList;
 import java.util.Collections;
@@ -274,7 +275,7 @@ public void customize(AutoConfigurationCustomizer autoConfiguration) {
             (metricExporter, configProperties) -> {
               if (metricExporter
                   instanceof AzureMonitorMetricExporterProvider.MarkerMetricExporter) {
-                return buildMetricExporter(configuration, telemetryClient, metricFilters);
+                return buildMetricExporter(configuration, telemetryClient, metricFilters, configProperties);
               } else {
                 return metricExporter;
               }
@@ -365,10 +366,16 @@ private static SpanExporter buildTraceExporter(
   private static MetricExporter buildMetricExporter(
       Configuration configuration,
       TelemetryClient telemetryClient,
-      List<MetricFilter> metricFilters) {
+      List<MetricFilter> metricFilters, ConfigProperties configProperties) {
+    
+    String otelMetricsEndpoint = configProperties.getString("otel.metrics.exporter.otlp.endpoint");
+    String otelMetricsExporter = configProperties.getString("otel.metrics.exporter");
+    boolean otlpEnabled = (otelMetricsExporter != null && !otelMetricsExporter.isEmpty()) &&
+                         (otelMetricsEndpoint != null && !otelMetricsEndpoint.isEmpty()); 
+    
     MetricDataMapper mapper =
         new MetricDataMapper(
-            telemetryClient::populateDefaults, configuration.preview.captureHttpServer4xxAsError);
+            telemetryClient::populateDefaults, configuration.preview.captureHttpServer4xxAsError, otlpEnabled);
     return new AgentMetricExporter(
         metricFilters, mapper, telemetryClient.getMetricsBatchItemProcessor());
   }