crash-reporter: disable device coredumps in verified mode

Device coredumps should only be available in developer mode.

BUG=None
TEST=link boot with devcoredump series

Signed-off-by: Kees Cook <keescook@chromium.org>
Change-Id: Ia86c32310887199b268b1f71221c6eb8a02f7827
Reviewed-on: https://chromium-review.googlesource.com/231386
Reviewed-by: Mike Frysinger <vapier@chromium.org>

crash_reporter/init/crash-reporter.conf

@@ -12,6 +12,12 @@ start on starting system-services
 
 pre-start script
   mkdir -p /var/spool
+
+  # Only allow device coredumps on a "developer system".
+  if ! is_developer_end_user; then
+    # consumer end-user - disable device coredumps, if driver exists.
+    echo 1 > /sys/class/devcoredump/disabled || true
+  fi
 end script
 
 # crash_reporter uses argv[0] as part of the command line for