Add UTs

Signed-off-by: Ashish Singh <[email protected]>

Author: ashking94

server/src/main/java/org/opensearch/snapshots/SnapshotsService.java

@@ -1327,7 +1327,8 @@ public void clusterStateProcessed(String source, ClusterState oldState, ClusterS
 
     private final Set<RepositoryShardId> currentlyCloning = Collections.synchronizedSet(new HashSet<>());
 
-    private void runReadyClone(
+    // Made to package private to be able to test the method in UTs
+    void runReadyClone(
         Snapshot target,
         SnapshotId sourceSnapshot,
         ShardSnapshotStatus shardStatusBefore,