Update git submodules

* Update tools/repohooks from branch 'master'
  to 99cb5dcd7fe4743c224c64dd006305dba8c58d8e
  - utils: add unittest coverage
    
    We had some Python 2/3 issues related to command output, but we
    didn't have any test coverage to catch it.  Add better unittest
    coverage for this module and fix up some issues it uncovers.
    
    Bug: 28298984
    Test: unittests pass for py2 & py3
    Change-Id: I13300428b4667393b29af466a795effd6374f392
    
1 file changed