NERtcMediaPriority constructor Null safety

1. nertc
2. nertc
3. NERtcMediaPriority
4. NERtcMediaPriority constructor

NERtcMediaPriority class

1. Constructors
2. NERtcMediaPriority
3. Properties
4. hashCode
5. runtimeType
6. Methods
7. noSuchMethod
8. toString
9. Operators
10. operator ==
11. Constants
12. high
13. normal