Merge "Switch to HexEncoding from ByteStringUtils"

import android.annotation.Nullable;

import android.content.pm.Signature;

import libcore.util.HexEncoding;

import java.io.ByteArrayOutputStream;

import java.io.IOException;

import java.security.MessageDigest;

     * @return The digest or null if an error occurs.

     */

    public static @Nullable String computeSha256Digest(@NonNull byte[] data) {

        return ByteStringUtils.toHexString(computeSha256DigestBytes(data));

        byte[] sha256DigestBytes = computeSha256DigestBytes(data);

        if (sha256DigestBytes == null) {

            return null;

        }

        return HexEncoding.encodeToString(sha256DigestBytes, true /* uppercase */);

    }

}