update samples

Author: wing328

samples/server/petstore/springboot-petstore-with-api-response-examples/src/main/java/org/openapitools/model/Order.java

@@ -45,7 +45,7 @@ public enum StatusEnum {
 
     DELIVERED("delivered");
 
-    private String value;
+    private final String value;
 
     StatusEnum(String value) {
       this.value = value;

samples/server/petstore/springboot-petstore-with-api-response-examples/src/main/java/org/openapitools/model/Pet.java

@@ -51,7 +51,7 @@ public enum StatusEnum {
 
     SOLD("sold");
 
-    private String value;
+    private final String value;
 
     StatusEnum(String value) {
       this.value = value;