Modify RTCSdpType to protect newRTCSdpType
Modify RTCPriorityType to protect methods
Modify RTCSctpTransportState to protect methods
Modify RTCRtcpMuxPolicy to protect methods
Modify RTCPeerConnectionState to protect methods
Modify RTCIceTransportPolicy to protect methods
Modify RTCIceGatheringState to protect methods
Modify RTCIceCredentialType to protect methods
Modify RTCIceConnectionState to protect methods
Modify RTCDtlsTransportState to protect methods
Modify RTCDataChannelState to protect methods
Modify RTCBundlePolicy to protect methods
Relates to #83
