Audio recording doesn't shutdown properly, cannot restart

[djee-ms]

Describe the bug Audio recording doesn't shutdown properly, and therefore cannot be restarted.

To Reproduce Steps to reproduce the behavior:

1. Attach an audio track to an audio transceiver
2. Establish a connection
3. Remove the audio track from the transceiver
4. Re-add the audio track on the transceiver

Expected behavior In step 3., audio stops being transmitted. Then in step 4. it starts again and the remote peer can hear the microphone recording again like after step 2.

Desktop (please complete the following information):

• OS: win32

Additional context AudioDeviceWindowsCore::RecordingIsInitialized() returns false after AudioDeviceWindowsCore::StopRecording() was called, but the _audioClient is left untouched, still initialized. When the WebRTC engine calls AudioDeviceWindowsCore::StartRecording() again in step 4., the code attempts to initialize _audioClient a second time, which logically fails with AUDCLNT_E_ALREADY_INITIALIZED.

[djee-ms]

(audio_device_core_win.cc:1176): IAudioClient::Initialize() failed:
(audio_device_core_win.cc:94): Core Audio method failed (hr=-2004287486)
(audio_device_core_win.cc:97): Error details: 쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌쳌�蚮翽
(audio_device_impl.cc:769): output: -1
(audio_state.cc:108): webrtc::internal::AudioState::AddSendingStream: Failed to initialize recording.

Callstack:

>   mrwebrtc.dll!CaptureDeviceInternal::InitTransport() Line 1175   C++
    mrwebrtc.dll!webrtc::AudioDeviceWindowsCore::InitRecording() Line 2236  C++
    mrwebrtc.dll!webrtc::AudioDeviceModuleImpl::InitRecording() Line 768    C++
    mrwebrtc.dll!webrtc::internal::AudioState::AddSendingStream(webrtc::AudioSendStream * stream, int sample_rate_hz, unsigned __int64 num_channels) Line 103   C++
    mrwebrtc.dll!webrtc::internal::AudioSendStream::Start() Line 392    C++
    mrwebrtc.dll!cricket::WebRtcVoiceMediaChannel::WebRtcAudioSendStream::UpdateSendState() Line 982    C++
    mrwebrtc.dll!cricket::WebRtcVoiceMediaChannel::WebRtcAudioSendStream::SetSource(cricket::AudioSource * source) Line 866 C++
    mrwebrtc.dll!cricket::WebRtcVoiceMediaChannel::SetLocalSource(unsigned int ssrc, cricket::AudioSource * source) Line 1944   C++
    mrwebrtc.dll!cricket::WebRtcVoiceMediaChannel::SetAudioSend(unsigned int ssrc, bool enable, const cricket::AudioOptions * options, cricket::AudioSource * source) Line 1779 C++

Note that additionally there's an uninitialized buffer access (security) issue in the message logging. FormatMessageW() returns messageLength == 0, which leaves errorText uninitialized, from which MAXERRORLENGTH characters are read and sent to RTC_LOG (which in our library is wired to a user callback so is trivially read back).