Ensure IAST smoke tests wait for the product to be started (#8312)

Author: manuel-alvarez-alvarez

dd-smoke-tests/iast-util/src/testFixtures/groovy/datadog/smoketest/AbstractIastServerSmokeTest.groovy

@@ -18,6 +18,7 @@ import java.util.concurrent.TimeoutException
 abstract class AbstractIastServerSmokeTest extends AbstractServerSmokeTest {
 
   private static final String TAG_NAME = '_dd.iast.json'
+  private static final String IAST_STARTED_MSG = 'IAST started'
 
   @Shared
   private final JsonSlurper jsonSlurper = new JsonSlurper()
@@ -32,6 +33,14 @@ abstract class AbstractIastServerSmokeTest extends AbstractServerSmokeTest {
     return {} // force traces decoding
   }
 
+  def setupSpec() {
+    try {
+      processTestLogLines { it.contains(IAST_STARTED_MSG) }
+    } catch (TimeoutException toe) {
+      throw new AssertionError("'$IAST_STARTED_MSG' not found in logs", toe)
+    }
+  }
+
   protected static String withSystemProperty(final String config, final Object value) {
     return "-Ddd.${config}=${value}"
   }