[Bugfix] Fix NPE in ReplicaShardAllocator (#13993)#14385

dblock merged 3 commits intoopensearch-project:mainopensearch-project/OpenSearch:mainfrom

DaniilRoman:fix-npe-in-replicashardallocatorDaniilRoman/OpenSearch:fix-npe-in-replicashardallocatorCopy head branch name to clipboard