digest for calling api in fibodo

Create Digest.java

public static String getDigest(String url){
        StringBuilder stringBuilder = new StringBuilder();
        String username = String.format("username=\"%1$s\"", BuildConfig.username);
        String realm = String.format("realm=\"%1$s\"", BuildConfig.realm);
        long nonceTime = Calendar.getInstance(TimeZone.getTimeZone("UTC")).getTimeInMillis()/1000;
        String nonce = String.format("nonce=\"%1$d\"", nonceTime);
        String uri = String.format("uri=\"%1$s\"", BuildConfig.api_path + BuildConfig.version + url);

        String HA1 = md5(BuildConfig.username + ":" + BuildConfig.realm + ":" + BuildConfig.password);
        String HA2 = md5("POST:"+ url);

        String response = String.format("response=\"%1$s\"", md5(HA1 + ":" + nonceTime + ":" +HA2));
        stringBuilder.append(username);
        stringBuilder.append(",");
        stringBuilder.append(realm);
        stringBuilder.append(",");
        stringBuilder.append(nonce);
        stringBuilder.append(",");
        stringBuilder.append(uri);
        stringBuilder.append(",");
        stringBuilder.append(response);
        return stringBuilder.toString();
    }