private void initCache() {
    // DCL based SecretCache setup, to ensure thread safety.
    if (cache == null) {
      synchronized (this) {
        if (cache == null) {
          cache = new SecretCache();
        }
      }
    }
  }
This load the secret from aws-secrets manager.
@param uri The uri should be of format: aws-sm:///{key-arn-or-name}
@return The secret fetched from AWS.
@throws IOException
ql/src/java/org/apache/hadoop/hive/ql/secrets/AWSSecretsManagerSecretSource.java