* Fixed suboptimal implementation of a magic sequence search on GCS. * Fix comparison. * Added buffered reader around plugged storage plugin such as GCS. * 1. Corrected some comments 2. Refactored GCS input stream check Co-authored-by: volodymyr.burenin <volodymyr.burenin@cloudkitchens.com> Co-authored-by: Nishith Agarwal <nagarwal@uber.com>