pre-upload: reject +x on files that should be -x

People sometimes add files with +x bits that don't make sense.
Add a check for many common data files and reject attempts to
add them with +x bits.

BUG=None
TEST=unittest passes
TEST=ran on some old bad commits and they were rejected

Change-Id: Id8de69b986e61b10ea17a4b4e4ceb18b09659259
Reviewed-on: https://chromium-review.googlesource.com/445983
Commit-Ready: Mike Frysinger <vapier@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Prathmesh Prabhu <pprabhu@chromium.org>
2 files changed