In virtual socket unittests replace MessageHandler with RepeatingTask

MessageHandlerAutoCleanup class is marked for removal

Bug: webrtc:11988
Change-Id: I44646b53e5a9520eb1d6c314b7bd580b1bdc0078
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/273940
Auto-Submit: Danil Chapovalov <danilchap@webrtc.org>
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Reviewed-by: Mirko Bonadei <mbonadei@webrtc.org>
Commit-Queue: Mirko Bonadei <mbonadei@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#37997}
diff --git a/rtc_base/BUILD.gn b/rtc_base/BUILD.gn
index 9a5f54f..c3e4be9 100644
--- a/rtc_base/BUILD.gn
+++ b/rtc_base/BUILD.gn
@@ -1627,6 +1627,7 @@
         "containers:unittests",
         "memory:unittests",
         "synchronization:mutex",
+        "task_utils:repeating_task",
         "third_party/base64",
         "third_party/sigslot",
       ]