NERtcAudioScenario constructor Null safety

1. netease_roomkit
2. netease_roomkit
3. NERtcAudioScenario
4. NERtcAudioScenario const constructor

NERtcAudioScenario enum

1. Constructors
2. NERtcAudioScenario
3. Values
4. scenarioDefault
5. scenarioSpeech
6. scenarioMusic
7. Properties
8. hashCode
9. index
10. runtimeType
11. Methods
12. noSuchMethod
13. toString
14. Operators
15. operator ==
16. Constants
17. values