factory-archiver: update the metadata for archived files

Implement the TODO of updating the metadata for archived files.

BUG=chrome-os-partner:27567
TEST=make lint LINT_WHITELIST=\
"py/lumberjack/archiver.py \
 py/lumberjack/archiver_cli.py \
 py/lumberjack/archiver_config.py \
 py/lumberjack/archiver_exception.py \
 py/lumberjack/archiver_unittest.py "
TEST=make test

Change-Id: I8fb808eacad98ed02244d408bf72f667ad784c9f
Reviewed-on: https://chromium-review.googlesource.com/196178
Tested-by: Chun-ta Lin <itspeter@chromium.org>
Reviewed-by: Ricky Liang <jcliang@chromium.org>
Commit-Queue: Chun-ta Lin <itspeter@chromium.org>
2 files changed