[apache#3941] fix(common): Fix potential bug of TopicDTO (apache#3942)

### What changes were proposed in this pull request?

return a new instance when `build()` called

### Why are the changes needed?

Fix: apache#3941 

### Does this PR introduce _any_ user-facing change?

no

### How was this patch tested?

by logic

common/src/main/java/com/datastrato/gravitino/dto/messaging/TopicDTO.java

@@ -92,11 +92,12 @@ public int hashCode() {
 
   /** A builder for constructing a Topic DTO. */
   public static class Builder {
-    private final TopicDTO topic;
+    private String name;
+    private String comment;
+    private Map<String, String> properties;
+    private AuditDTO audit;
 
-    private Builder() {
-      topic = new TopicDTO();
-    }
+    private Builder() {}
 
     /**
      * Sets the name of the topic.
@@ -105,7 +106,7 @@ private Builder() {
      * @return The builder instance.
      */
     public Builder withName(String name) {
-      topic.name = name;
+      this.name = name;
       return this;
     }
 
@@ -116,7 +117,7 @@ public Builder withName(String name) {
      * @return The builder instance.
      */
     public Builder withComment(String comment) {
-      topic.comment = comment;
+      this.comment = comment;
       return this;
     }
 
@@ -127,7 +128,7 @@ public Builder withComment(String comment) {
      * @return The builder instance.
      */
     public Builder withProperties(Map<String, String> properties) {
-      topic.properties = properties;
+      this.properties = properties;
       return this;
     }
 
@@ -138,13 +139,13 @@ public Builder withProperties(Map<String, String> properties) {
      * @return The builder instance.
      */
     public Builder withAudit(AuditDTO audit) {
-      topic.audit = audit;
+      this.audit = audit;
       return this;
     }
 
     /** @return The constructed Topic DTO. */
     public TopicDTO build() {
-      return topic;
+      return new TopicDTO(name, comment, properties, audit);
     }
   }
 }