fix(java): fix reserved keyword conflict (#1819)

## What does this PR do?

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## Related issues
Closes #1818 
## Does this PR introduce any user-facing change?

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- [ ] Does this PR introduce any public API change?
- [ ] Does this PR introduce any binary protocol compatibility change?

## Benchmark

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java/fury-core/src/main/java/org/apache/fury/codegen/CodegenContext.java

@@ -124,7 +124,7 @@ public class CodegenContext {
   private static Map<String, Map<String, Boolean>> nameConflicts = new ConcurrentHashMap<>();
 
   Map<String, Long> newValNameIds = new HashMap<>();
-  Set<String> valNames = new HashSet<>();
+  Set<String> valNames = new HashSet<>(JAVA_RESERVED_WORDS);
 
   /**
    * State used for expression elimination/reuse.

java/fury-core/src/test/java/org/apache/fury/codegen/CodegenContextTest.java

@@ -82,6 +82,12 @@ public void testNewName() {
     }
   }
 
+  @Test
+  public void testNewNameKeywordConflict() {
+    Assert.assertNotEquals(new CodegenContext().newName("default"), "default");
+    Assert.assertNotEquals(new CodegenContext().newNames("default", "abc")[0], "default");
+  }
+
   @Test
   public void testAddStaticField() {
     CodegenContext ctx = new CodegenContext();