build_packages.sh: Migrate debug symbols

Migrate the install debug symbols logic to Python. Remove the unused
flag.

BUG=b:218522022
TEST=CQ

Cq-Depend: chromium:3609013
Change-Id: Ie8810da7855b8a87ee474c3e638d524cc73533ae
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosutils/+/3608818
Tested-by: Cindy Lin <xcl@google.com>
Commit-Queue: Cindy Lin <xcl@google.com>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
1 file changed