Fix auto-bisect presubmit so that it checks config files again.
When I changed this PRESUBMIT.py in http://crrev.com/292434, I didn't properly test it, so it hasn't actually been checking auto_bisect/bisect.cfg as it was supposed to.
This change makes so that the files listed in the CONFIG_FILES list here will be checked (including run-perf-test.cfg, even though it's outside of the auto_bisect directory).
BUG=
Review URL: https://codereview.chromium.org/
669543002
Cr-Commit-Position: refs/heads/master@{#300598}