Guard includes for iwyu

Author: chusitoo

ext/src/http/client/curl/http_operation_curl.cc

@@ -4,8 +4,12 @@
 #include <curl/curl.h>
 #include <curl/curlver.h>
 #include <curl/system.h>
+
+#ifdef ENABLE_OTLP_RETRY_PREVIEW
+#  include <array>
+#endif  // ENABLE_OTLP_RETRY_PREVIEW
+
 #include <algorithm>
-#include <array>
 #include <atomic>
 #include <chrono>
 #include <cmath>

ext/test/http/curl_http_test.cc

@@ -1,11 +1,14 @@
 // Copyright The OpenTelemetry Authors
 // SPDX-License-Identifier: Apache-2.0
 
-#include <curl/curl.h>
 #include <curl/curlver.h>
-#include "gmock/gmock.h"
 #include "gtest/gtest.h"
 
+#ifdef ENABLE_OTLP_RETRY_PREVIEW
+#  include <curl/curl.h>
+#  include "gmock/gmock.h"
+#endif  // ENABLE_OTLP_RETRY_PREVIEW
+
 #include <string.h>
 #include <algorithm>
 #include <atomic>