gblsigntool: Import from aosp/gbl-mainline

Test: atest --host gblsigntool_test
Change-Id: Iece96409b32451095a763970b9b5a5908de6ca23
12 files changed
tree: 6a80c33041b3f2eeb0c2b71336ec43e49761a5c3
  1. gbl/
  2. libxbc/
  3. vts/
  4. .clang-format
  5. .gitignore
  6. LICENSE
  7. OWNERS