Android : onconnection falied Googleclient api

I have created a project where i pick picture from camera and then upload to my googleDrive .

i use code as and it upload image to googledrive well. protected void upload(final File file) { Log.v(TAG, "uploading " + file);

    new GoogelDriveUploader(mClient) 
    {
        @Override
        protected void onPostExecute(DriveFile result) 
        {
            super.onPostExecute(result);
            if (result != null) 
            {
                Log.v(TAG, "Uploaded to Google Drive"+file + " to " + result.getDriveId());
                Toast.makeText(getApplicationContext(), "Uploaded to Google Drive",              Toast.LENGTH_LONG).show();
                //file.delete();
            } 
            else
            {
                Toast.makeText(getApplicationContext(), "Upload failed", Toast.LENGTH_LONG).show();
            }
        }
    }.execute(file);
}

but when i create sign apk then download from googleplay store then connection failed with googledrive and Unkown issue with google play ervices error come. i dont know whats the problem.