Update Importance and Visibility enums to use @get:JsonValue annotation

Author: Choochmeque

android/src/main/java/app/tauri/notification/ChannelManager.kt

@@ -13,15 +13,15 @@ import app.tauri.annotation.InvokeArg
 import app.tauri.plugin.Invoke
 import com.fasterxml.jackson.annotation.JsonValue
 
-enum class Importance(@JsonValue val value: Int) {
+enum class Importance(@get:JsonValue val value: Int) {
   None(0),
   Min(1),
   Low(2),
   Default(3),
   High(4);
 }
 
-enum class Visibility(@JsonValue val value: Int) {
+enum class Visibility(@get:JsonValue val value: Int) {
   Secret(-1),
   Private(0),
   Public(1);