message: add thread check in DcSctpTransport::OnTransportReadPacket
  Cr-Commit-Position: refs/heads/main@{#35679}
diff: @@ -525,6 +525,7 @@ void DcSctpTransport::OnTransportReadPacket(
  size_t length,
  const int64_t& /* packet_time_us */,
  int flags) {
  + RTC_DCHECK_RUN_ON(network_thread_);
  if (flags) {
  // We are only interested in SCTP packets.
  return;
  