### Description

Currently, the [`tryAuthenticateToken`](https://github.com/elastic/elasticsearch/blob/55088d154d1764a6d4fa8e9078bde9da1e9ff9a5/x-pack/plugin/security/src/main/java/org/elasticsearch/xpack/security/authc/TokenService.java#L458) method calls `decodeAndValidateToken` which ends up sending two `GetRequest` for the same token ID. First in [`decodeToken`](https://github.com/elastic/elasticsearch/blob/55088d154d1764a6d4fa8e9078bde9da1e9ff9a5/x-pack/plugin/security/src/main/java/org/elasticsearch/xpack/security/authc/TokenService.java#L602) and second in [`checkIfTokenIsValid`](https://github.com/elastic/elasticsearch/blob/55088d154d1764a6d4fa8e9078bde9da1e9ff9a5/x-pack/plugin/security/src/main/java/org/elasticsearch/xpack/security/authc/TokenService.java#L1977). The second call is unnecessary as we already fetched the access token in the first call, it's just simply dropped. We should refactor these two methods to avoid sending second get request just to validate the access token.
x-pack/plugin/security/src/main/java/org/elasticsearch/xpack/security/authc/TokenService.java
});
        }
        @Override
        public void close() {
            keyAndTimestamp.getKey().close();
        }
        BytesKey getKeyHash() {
            return keyHash;
        }
        private static BytesKey calculateKeyHash(SecureString key) {
            MessageDigest messageDigest = sha256();
            BytesRefBuilder b = new BytesRefBuilder();
            try {
                b.copyChars(key);
                BytesRef bytesRef = b.toBytesRef();
                try {
                    messageDigest.update(bytesRef.bytes, bytesRef.offset, bytesRef.length);
                    return new BytesKey(Arrays.copyOfRange(messageDigest.digest(), 0, 8));
                } finally {
                    Arrays.fill(bytesRef.bytes, (byte) 0x00);
                }
            } finally {
                Arrays.fill(b.bytes(), (byte) 0x00);
            }
        }
        BytesKey getSalt() {
            return salt;
        }
    }
    private static final class TokenKeys {