use Any? over Any

Author: tbarbugli

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractKotlinCodegen.java

@@ -230,7 +230,7 @@ public AbstractKotlinCodegen() {
         typeMapping.put("binary", "kotlin.ByteArray");
         typeMapping.put("Date", "java.time.LocalDate");
         typeMapping.put("DateTime", "java.time.OffsetDateTime");
-        typeMapping.put("AnyType", "kotlin.Any");
+        typeMapping.put("AnyType", "kotlin.Any?");
 
         instantiationTypes.put("array", "kotlin.collections.ArrayList");
         instantiationTypes.put("list", "kotlin.collections.ArrayList");