Add missing absl::optional includes

Bug: None
Change-Id: I4abece77b021a866175253cbb2bd212ff618910c
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/341022
Auto-Submit: Danil Chapovalov <danilchap@webrtc.org>
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Reviewed-by: Jeremy Leconte <jleconte@google.com>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#41813}

modules/rtp_rtcp/source/rtcp_packet/transport_feedback_unittest.cc

@@ -14,6 +14,7 @@
 #include <memory>
 #include <utility>
 
+#include "absl/types/optional.h"
 #include "api/array_view.h"
 #include "api/units/time_delta.h"
 #include "api/units/timestamp.h"

rtc_base/task_utils/BUILD.gn

@@ -42,6 +42,9 @@ if (rtc_include_tests) {
       "../../system_wrappers:system_wrappers",
       "../../test:test_support",
     ]
-    absl_deps = [ "//third_party/abseil-cpp/absl/functional:any_invocable" ]
+    absl_deps = [
+      "//third_party/abseil-cpp/absl/functional:any_invocable",
+      "//third_party/abseil-cpp/absl/types:optional",
+    ]
   }
 }

rtc_base/task_utils/repeating_task_unittest.cc

@@ -14,6 +14,7 @@
 #include <memory>
 
 #include "absl/functional/any_invocable.h"
+#include "absl/types/optional.h"
 #include "api/task_queue/task_queue_base.h"
 #include "api/task_queue/test/mock_task_queue_base.h"
 #include "api/units/time_delta.h"