NERtcChannelMediaRelayEvent constructor Null safety

1. nertc
2. nertc
3. NERtcChannelMediaRelayEvent
4. NERtcChannelMediaRelayEvent constructor

NERtcChannelMediaRelayEvent class

1. Constructors
2. NERtcChannelMediaRelayEvent
3. Properties
4. hashCode
5. runtimeType
6. Methods
7. noSuchMethod
8. toString
9. Operators
10. operator ==
11. Constants
12. audioSentSuccess
13. connected
14. connecting
15. disconnect
16. failure
17. otherStreamSentSuccess
18. videoSentSuccess