Include optional.h in rtc_event_log_parser_new.cc

Bug: None
Change-Id: I5ef8227ca4763232717808aae2f6395ce66a4ed9
Reviewed-on: https://webrtc-review.googlesource.com/103160
Reviewed-by: Björn Terelius <terelius@webrtc.org>
Commit-Queue: Elad Alon <eladalon@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24927}

logging/BUILD.gn

@@ -288,6 +288,7 @@ if (rtc_enable_protobuf) {
       "../rtc_base:protobuf_utils",
       "../rtc_base:rtc_base_approved",
       "//third_party/abseil-cpp/absl/memory",
+      "//third_party/abseil-cpp/absl/types:optional",
     ]
   }
 

logging/rtc_event_log/rtc_event_log_parser_new.cc

@@ -21,6 +21,7 @@
 #include <utility>
 
 #include "absl/memory/memory.h"
+#include "absl/types/optional.h"
 #include "api/rtp_headers.h"
 #include "api/rtpparameters.h"
 #include "logging/rtc_event_log/rtc_event_log.h"