* [kotlin][client] Kotlinx Serialization cleanup
* [kotlin][client] Kotlinx Serialization cleanup
* [kotlin][client] add support for unknown default case with Kotlinx Serialization
* [kotlin][client] add support for unknown default case with Kotlinx Serialization
* [kotlin][client] add support for unknown default case with Kotlinx Serialization
* [kotlin][client] improve Kotlinx Serialization naming
* [kotlin][client] improve Kotlinx Serialization naming
* [Kotlin] enumPropertyNaming UPPERCASE should separate words with _
* Add unit cases for issue 4062
Co-authored-by: William Cheng <wing328hk@gmail.com>