Updating Cluster Stats Optimisation Versions to 2.16 (opensearch-project#14914)

* Updating Cluster Stats Optimisation Versions to 2.16

Signed-off-by: Pranshu Shukla <pranshushukla06@gmail.com>

Author: Pranshu-S

server/src/main/java/org/opensearch/action/admin/cluster/stats/ClusterStatsNodeResponse.java

@@ -77,7 +77,7 @@ public ClusterStatsNodeResponse(StreamInput in) throws IOException {
         }
         this.nodeInfo = new NodeInfo(in);
         this.nodeStats = new NodeStats(in);
-        if (in.getVersion().onOrAfter(Version.V_3_0_0)) {
+        if (in.getVersion().onOrAfter(Version.V_2_16_0)) {
             this.shardsStats = in.readOptionalArray(ShardStats::new, ShardStats[]::new);
             this.aggregatedNodeLevelStats = in.readOptionalWriteable(AggregatedNodeLevelStats::new);
         } else {
@@ -156,7 +156,7 @@ public void writeTo(StreamOutput out) throws IOException {
         }
         nodeInfo.writeTo(out);
         nodeStats.writeTo(out);
-        if (out.getVersion().onOrAfter(Version.V_3_0_0)) {
+        if (out.getVersion().onOrAfter(Version.V_2_16_0)) {
             if (aggregatedNodeLevelStats != null) {
                 out.writeOptionalArray(null);
                 out.writeOptionalWriteable(aggregatedNodeLevelStats);

server/src/main/java/org/opensearch/action/admin/cluster/stats/ClusterStatsRequest.java

@@ -50,7 +50,7 @@ public class ClusterStatsRequest extends BaseNodesRequest<ClusterStatsRequest> {
 
     public ClusterStatsRequest(StreamInput in) throws IOException {
         super(in);
-        if (in.getVersion().onOrAfter(Version.V_3_0_0)) {
+        if (in.getVersion().onOrAfter(Version.V_2_16_0)) {
             useAggregatedNodeLevelResponses = in.readOptionalBoolean();
         }
     }
@@ -76,7 +76,7 @@ public void useAggregatedNodeLevelResponses(boolean useAggregatedNodeLevelRespon
     @Override
     public void writeTo(StreamOutput out) throws IOException {
         super.writeTo(out);
-        if (out.getVersion().onOrAfter(Version.V_3_0_0)) {
+        if (out.getVersion().onOrAfter(Version.V_2_16_0)) {
             out.writeOptionalBoolean(useAggregatedNodeLevelResponses);
         }
     }