Correct the version post backport to 2.18 instead of current (opensearch-project#16127)

Signed-off-by: Gaurav Bafna <gbbafna@amazon.com>

Author: gbbafna

server/src/main/java/org/opensearch/cluster/SnapshotsInProgress.java

@@ -412,7 +412,7 @@ private Entry(StreamInput in) throws IOException {
             } else {
                 remoteStoreIndexShallowCopy = false;
             }
-            if (in.getVersion().onOrAfter(Version.CURRENT)) {
+            if (in.getVersion().onOrAfter(Version.V_2_18_0)) {
                 remoteStoreIndexShallowCopyV2 = in.readBoolean();
             } else {
                 remoteStoreIndexShallowCopyV2 = false;
@@ -886,7 +886,7 @@ public void writeTo(StreamOutput out) throws IOException {
             if (out.getVersion().onOrAfter(Version.V_2_9_0)) {
                 out.writeBoolean(remoteStoreIndexShallowCopy);
             }
-            if (out.getVersion().onOrAfter(Version.CURRENT)) {
+            if (out.getVersion().onOrAfter(Version.V_2_18_0)) {
                 out.writeBoolean(remoteStoreIndexShallowCopyV2);
             }
         }