[#380] fix: Kotli MetaData experiments

(cherry picked from commit 38528b4)

Author: MateuszNaKodach

kotlin/src/main/kotlin/org/axonframework/extensions/kotlin/serialization/AxonSerializers.kt

@@ -112,7 +112,7 @@ val `AxonSerializersModule` = SerializersModule {
         subclass(MultipleInstancesResponseTypeSerializer)
         subclass(ArrayResponseTypeSerializer)
     }
-    contextual(MetaData::class) { MapSerializer(String.serializer(), String.serializer()) }
+    contextual(MetaData::class) { MetaDataSerializer }
 }
 
 /**

kotlin/src/test/kotlin/org/axonframework/extensions/kotlin/serializer/AxonSerializersTest.kt

@@ -175,18 +175,6 @@ internal class AxonSerializersTest {
         assertEquals(responseType, serializer.deserializeResponseType(responseType.javaClass.name, json))
     }
 
-    @Test
-    fun metaDataSerialization() {
-        val metaData = MetaData.emptyInstance()
-        val json = """{}"""
-        val serialized = serializer.serialize(metaData, String::class.java).data
-
-        val serializedType = SimpleSerializedType(type, null)
-        val serializedToken = SimpleSerializedObject(json, String::class.java, serializedType)
-        return deserialize(serializedToken)
-        assertEquals(json, serialized)
-    }
-
     @Test
     fun metaDataSerialization2() {
         val metaData = MetaData.with("key", "value")