ActiveLiveness constructor Null safety

1. face_sdk
2. face_sdk
3. ActiveLiveness
4. ActiveLiveness const constructor

ActiveLiveness enum

1. Constructors
2. ActiveLiveness
3. Values
4. ALL_CHECKS_PASSED
5. CURRENT_CHECK_PASSED
6. CHECK_FAIL
7. WAITING_FACE_ALIGN
8. IN_PROGRESS
9. NOT_COMPUTED
10. Properties
11. hashCode
12. index
13. runtimeType
14. Methods
15. noSuchMethod
16. toString
17. Operators
18. operator ==
19. Constants
20. values