Fix flaky InProduct enablement smoke test (#8627)

Wait for feature started before sending request to avoid racy startup

Author: jpbempel

dd-java-agent/agent-debugger/src/main/java/com/datadog/debugger/agent/DebuggerAgent.java

@@ -172,6 +172,7 @@ public static void startDynamicInstrumentation() {
     } else {
       LOGGER.debug("No configuration poller available from SharedCommunicationObjects");
     }
+    LOGGER.info("Started Dynamic Instrumentation");
   }
 
   public static void stopDynamicInstrumentation() {
@@ -205,6 +206,7 @@ public static void startExceptionReplay() {
             Duration.ofSeconds(config.getDebuggerExceptionCaptureInterval()),
             config.getDebuggerMaxExceptionPerSecond());
     DebuggerContext.initExceptionDebugger(exceptionDebugger);
+    LOGGER.info("Started Exception Replay");
   }
 
   public static void stopExceptionReplay() {
@@ -230,6 +232,7 @@ public static void startCodeOriginForSpans() {
     initClassNameFilter();
     DebuggerContext.initClassNameFilter(classNameFilter);
     DebuggerContext.initCodeOrigin(new DefaultCodeOriginRecorder(config, configurationUpdater));
+    LOGGER.info("Started Code Origin for spans");
   }
 
   public static void stopCodeOriginForSpans() {

dd-smoke-tests/debugger-integration-tests/src/main/java/datadog/smoketest/debugger/ServerDebuggerTestApplication.java

@@ -76,7 +76,7 @@ protected void stop() {
   }
 
   protected void waitForInstrumentation(String className) {
-    System.out.println("waitForInstrumentation on " + className + " from: " + lastMatchedLine);
+    System.out.println("waitForInstrumentation on " + className);
     try {
       lastMatchedLine =
           TestApplicationHelper.waitForInstrumentation(LOG_FILENAME, className, lastMatchedLine);

dd-smoke-tests/debugger-integration-tests/src/test/java/datadog/smoketest/InProductEnablementIntegrationTest.java

@@ -3,7 +3,6 @@
 import static datadog.smoketest.debugger.TestApplicationHelper.waitForSpecificLine;
 
 import com.datadog.debugger.probe.LogProbe;
-import datadog.trace.test.util.Flaky;
 import java.io.IOException;
 import java.nio.file.Path;
 import java.util.ArrayList;
@@ -53,7 +52,6 @@ void testDynamicInstrumentationEnablementStaticallyDisabled() throws Exception {
     waitForSpecificLine(appUrl, "Feature dynamic.instrumentation.enabled is explicitly disabled");
   }
 
-  @Flaky
   @Test
   @DisplayName("testExceptionReplayEnablement")
   void testExceptionReplayEnablement() throws Exception {
@@ -70,7 +68,7 @@ void testExceptionReplayEnablement() throws Exception {
   }
 
   private void waitForFeatureStarted(String appUrl, String feature) throws IOException {
-    String line = "INFO com.datadog.debugger.agent.DebuggerAgent - Starting " + feature;
+    String line = "INFO com.datadog.debugger.agent.DebuggerAgent - Started " + feature;
     waitForSpecificLine(appUrl, line);
     LOG.info("feature {} started", feature);
   }