message: Improve logging of DTLS transport handshake
  showing whether the DTLS transport is active and will send
  a client hello or not.
  Cr-Commit-Position: refs/heads/main@{#38886}
diff: @@ -758,7 +758,9 @@ void DtlsTransport::MaybeStartDtls() {
  set_dtls_state(webrtc::DtlsTransportState::kFailed);
  return;
  }
  - RTC_LOG(LS_INFO) << ToString() << ": DtlsTransport: Started DTLS handshake";
  + RTC_LOG(LS_INFO) << ToString()
  + << ": DtlsTransport: Started DTLS handshake active="
  + << IsDtlsActive();
  set_dtls_state(webrtc::DtlsTransportState::kConnecting);
  // Now that the handshake has started, we can process a cached ClientHello
  // (if one exists).
  