message: Update SCTP test to use C++ lambdas instead of rtc::Bind
  Cr-Commit-Position: refs/heads/master@{#33018}
diff: @@ -220,16 +220,14 @@ class SctpDataSender final {
  case cricket::SDR_BLOCK:
  // retry after timeout
  invoker_.AsyncInvokeDelayed<void>(
  - RTC_FROM_HERE, thread_,
  - rtc::Bind(&SctpDataSender::SendNextMessage, this), 500);
  + RTC_FROM_HERE, thread_, [this] { SendNextMessage(); }, 500);
  break;
  case cricket::SDR_SUCCESS:
  // send next
  num_bytes_sent_ += payload_.size();
  ++num_messages_sent_;
  - invoker_.AsyncInvoke<void>(
  - RTC_FROM_HERE, thread_,
  - rtc::Bind(&SctpDataSender::SendNextMessage, this));
  + invoker_.AsyncInvoke<void>(RTC_FROM_HERE, thread_,
  + [this] { SendNextMessage(); });
  break;
  case cricket::SDR_ERROR:
  // give up
  