Fix a MultiCodecMergeIT test fail.

Signed-off-by: Mulugeta Mammo <mulugeta.mammo@intel.com>

Author: mulugetam

src/internalClusterTest/java/org/opensearch/index/codec/MultiCodecMergeIT.java

@@ -25,6 +25,7 @@
 import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
 import java.util.UUID;
@@ -52,30 +53,24 @@ protected Collection<Class<? extends Plugin>> nodePlugins() {
 
     public void testForceMergeMultipleCodecs() throws ExecutionException, InterruptedException {
 
-        Map<String, String> codecMap = Map.of(
-            "best_compression",
-            "BEST_COMPRESSION",
-            "zlib",
-            "BEST_COMPRESSION",
-            "zstd_no_dict",
-            "ZSTD_NO_DICT",
-            "zstd",
-            "ZSTD",
-            "default",
-            "BEST_SPEED",
-            "lz4",
-            "BEST_SPEED"
-        );
-
-        if (QatZipperFactory.isQatAvailable()) {
-            codecMap.put("QAT_LZ4", "qat_lz4");
-            codecMap.put("QAT_DEFLATE", "qat_deflate");
-        }
+        Map<String, String> codecMap = new HashMap<String, String>() {
+            {
+                put("best_compression", "BEST_COMPRESSION");
+                put("zlib", "BEST_COMPRESSION");
+                put("zstd_no_dict", "ZSTD_NO_DICT");
+                put("zstd", "ZSTD");
+                put("default", "BEST_SPEED");
+                put("lz4", "BEST_SPEED");
+                if (QatZipperFactory.isQatAvailable()) {
+                    put("qat_lz4", "QAT_LZ4");
+                    put("qat_deflate", "QAT_DEFLATE");
+                }
+            }
+        };
 
         for (Map.Entry<String, String> codec : codecMap.entrySet()) {
             forceMergeMultipleCodecs(codec.getKey(), codec.getValue(), codecMap);
         }
-
     }
 
     private void forceMergeMultipleCodecs(String finalCodec, String finalCodecMode, Map<String, String> codecMap) throws ExecutionException,