Add instrumentation config id

Same as DataDog/dd-trace-py#8783 but for Java.

Author: Kyle-Verhoog

telemetry/src/main/java/datadog/telemetry/TelemetryRequest.java

@@ -115,6 +115,16 @@ public void writeInstallSignature() {
     }
   }
 
+  public void writeInstrumentationConfigId() {
+    String instrumentationConfigId = System.getenv("DD_INSTRUMENTATION_CONFIG_ID");
+
+    try {
+      requestBody.writeInstrumentationConfigId(instrumentationConfigId);
+    } catch (IOException e) {
+      throw new TelemetryRequestBody.SerializationException("instrumentation-config-id", e);
+    }
+  }
+
   public void writeIntegrations() {
     if (!isWithinSizeLimits() || !eventSource.hasIntegrationEvent()) {
       return;

telemetry/src/main/java/datadog/telemetry/TelemetryRequestBody.java

@@ -301,6 +301,13 @@ public void writeInstallSignature(String installId, String installType, String i
     bodyWriter.endObject();
   }
 
+  public void writeInstrumentationConfigId(String instrumentationConfigId) throws IOException {
+    if (instrumentationConfigId == null) {
+      return;
+    }
+    bodyWriter.name("instrumentation_config_id").value(instrumentationConfigId);
+  }
+
   @Nullable
   @Override
   public MediaType contentType() {

telemetry/src/test/groovy/datadog/telemetry/TelemetryServiceSpecification.groovy

@@ -441,6 +441,27 @@ class TelemetryServiceSpecification extends DDSpecification {
     "68e75c77-57ca-4a12-adfc-575c4b05fc44" | "k8s_single_step" | "1993188215"
   }
 
+  def 'app started must have instrumentation config id'() {
+    setup:
+    injectEnvConfig("INSTRUMENTATION_CONFIG_ID", configId)
+
+    TestTelemetryRouter testHttpClient = new TestTelemetryRouter()
+    TelemetryService telemetryService = new TelemetryService(testHttpClient, 10000, false)
+
+    when: 'first iteration'
+    testHttpClient.expectRequest(TelemetryClient.Result.SUCCESS)
+    telemetryService.sendAppStartedEvent()
+
+    then: 'app-started'
+    testHttpClient.assertRequestBody(RequestType.APP_STARTED).assertPayload().installSignature(installId, installType, installTime)
+    testHttpClient.assertNoMoreRequests()
+
+    where:
+    configId
+    null
+    "68e75c99-57ca-4a12-adfc-575c4b05fcbe"
+  }
+
   def 'app-started must include activated products info'() {
     setup:
     injectEnvConfig(Strings.toEnvVar(AppSecConfig.APPSEC_ENABLED), appsecConfig)