Extend "non-release" check to session manager use-flags.

Since we've moved away from flag-files in session manager to
enable certain dev/test-mode features, our strategy of checking
for those flag files on the signer fell behind. This test adopts
a scheme that any use flag starting with "test_" or "dangerous_"
is blacklisted from release signing.

BUG=chromium-os:32430
TEST=ran the script against both a 'base' and 'test' image
from the builder/ToT. Passes/fails as expected.

Change-Id: I54d6ef17d52371c7543d5705e0939e000db85e51
Reviewed-on: https://gerrit.chromium.org/gerrit/29034
Reviewed-by: Chris Masone <cmasone@chromium.org>
Tested-by: Jim Hebert <jimhebert@chromium.org>
Commit-Ready: Jim Hebert <jimhebert@chromium.org>
1 file changed