CompletableFuture<Boolean> deleteFileAsync(String containerName, String fileName) {
    return FutureUtils.orTimeout(storageClient.deleteFile(containerName, fileName), uploadTimeout);
  }
Delete a file from blob storage asynchronously, if it exists.
@param containerName name of the container containing file to delete.
@param fileName name of the file to delete.
@return a CompletableFuture of type Boolean that will eventually complete successfully when the file is deleted or
        will complete exceptionally if an error occurs.
ambry-cloud/src/main/java/com/github/ambry/cloud/azure/AzureBlobDataAccessor.java