[K2] Properly serialize constant values

#KT-56190 Fixed

native/native.tests/testData/klibContents/builtinsSerializer/nestedClassesAndObjects.kt

@@ -1,5 +1,3 @@
-// KT-56190 K2 does not emit const initializers
-// MUTED_WHEN: K2
 package test
 
 class ClassA {
@@ -18,7 +16,9 @@ class ClassA {
     inner class classC {
         val memberFromC: Int = 200
     }
+}
 
+class E {
     companion object {
         val stat: Int = 250
 
@@ -26,7 +26,9 @@ class ClassA {
             val memberFromD: Int = 275
         }
     }
+}
 
+class F {
     object ObjA {
         val memberFromObjA: Int = 300
     }