如何在android studio中使用URL Shortener API客户端库？

我在我的Android应用程序中使用Google+登录，我想向我的web服务器发送身份验证令牌 [ 并使用以下代码生成idToken

private class GetIdTokenTask extends AsyncTask<String, Void, String> {

    @Override
    protected String doInBackground(String... params) {
        String accountName = Plus.AccountApi.getAccountName(mGoogleApiClient);
        Account account = new Account(accountName, GoogleAuthUtil.GOOGLE_ACCOUNT_TYPE);
        String scopes = "audience:server:client_id:" + Constants.SERVER_CLIENT_ID; // Not the app's client ID.
        String idToken = "";
        try {
            idToken = GoogleAuthUtil.getToken(getApplicationContext(), account, scopes);
        } catch (IOException e) {
            Log.e(TAG, "Error retrieving ID token.", e);
        } catch (GoogleAuthException e) {
            Log.e(TAG, "Error retrieving ID token.", e);
        }
        return idToken;
    }

    @Override
    protected void onPostExecute(String result) {
        authToken=result;
        Log.i(TAG, "ID token: " + result);

    }

}

后端程序员建议我使用 urlshortener和 userinfo.email 要得到那种代币。我怎样才能得到这种代币？ 我正在使用GoogleAppClient连接google plus和驱动api，代码如下：

if (mGoogleApiClient == null) {
            mGoogleApiClient = new GoogleApiClient.Builder(this)
                    .addApi(Drive.API)
                    .addScope(Drive.SCOPE_FILE)
                    .addApi(Plus.API)
                    .addScope(new Scope("profile"))
                    .addScope(Drive.SCOPE_APPFOLDER) // required for App Folder sample
                    .addConnectionCallbacks(this)
                    .addOnConnectionFailedListener(this)
                    .build();
        }

        findViewById(R.id.sign_in_button).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                mGoogleApiClient.connect();

            }
        });

如何以我上面描述的缩短格式获取auth令牌

if (mGoogleApiClient == null) {
            mGoogleApiClient = new GoogleApiClient.Builder(this)
                    .addApi(Drive.API)
                    .addScope(Drive.SCOPE_FILE)
                    .addApi(Plus.API)
                    .addScope(new Scope("profile"))
                    .addScope(Drive.SCOPE_APPFOLDER) // required for App Folder sample
                    .addConnectionCallbacks(this)
                    .addOnConnectionFailedListener(this)
                    .build();
        }

        findViewById(R.id.sign_in_button).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                mGoogleApiClient.connect();

            }
        });