[KYUUBI #6727] replace immutable empty list and map in BatchRequest i…

…nitialization

# 🔍 Description
## Issue References 🔗

This pull request fixes #

## Describe Your Solution 🔧

- replace immutable empty list and map with mutable one for BatchRequest initialization, for easier BatchRequest construction for rest-client use

## Types of changes 🔖

- [ ] Bugfix (non-breaking change which fixes an issue)
- [ ] New feature (non-breaking change which adds functionality)
- [ ] Breaking change (fix or feature that would cause existing functionality to change)

## Test Plan 🧪

#### Behavior Without This Pull Request ⚰️

#### Behavior With This Pull Request 🎉

#### Related Unit Tests

---

# Checklist 📝

- [ ] This patch was not authored or co-authored using [Generative Tooling](https://www.apache.org/legal/generative-tooling.html)

**Be nice. Be informative.**

Closes #6727 from bowenliang123/batchapi-emptylist.

Closes #6727

9d6a04c [Bowen Liang] update

Authored-by: Bowen Liang <[email protected]>
Signed-off-by: Bowen Liang <[email protected]>

kyuubi-rest-client/src/main/java/org/apache/kyuubi/client/api/v1/dto/BatchRequest.java

@@ -17,10 +17,7 @@
 
 package org.apache.kyuubi.client.api.v1.dto;
 
-import java.util.Collections;
-import java.util.List;
-import java.util.Map;
-import java.util.Objects;
+import java.util.*;
 import org.apache.commons.lang3.builder.ReflectionToStringBuilder;
 import org.apache.commons.lang3.builder.ToStringStyle;
 
@@ -29,9 +26,9 @@ public class BatchRequest {
   private String resource;
   private String className;
   private String name;
-  private Map<String, String> conf = Collections.emptyMap();
-  private List<String> args = Collections.emptyList();
-  private Map<String, String> extraResourcesMap = Collections.emptyMap();
+  private Map<String, String> conf = new HashMap<>(0);
+  private List<String> args = new ArrayList<>(0);
+  private Map<String, String> extraResourcesMap = new HashMap<>(0);
 
   public BatchRequest() {}
 
@@ -91,7 +88,7 @@ public void setName(String name) {
 
   public Map<String, String> getConf() {
     if (null == conf) {
-      return Collections.emptyMap();
+      return new HashMap<>(0);
     }
     return conf;
   }
@@ -102,7 +99,7 @@ public void setConf(Map<String, String> conf) {
 
   public List<String> getArgs() {
     if (null == args) {
-      return Collections.emptyList();
+      return new ArrayList<>(0);
     }
     return args;
   }