AUM: create noticeable changes for manual tests of offline update

With this change we prepare the "outdated" commit without the
content of some directories. This allows to provide the significant
difference between "original" and "outdated" commits, so it is easy
to check it in booted deployment.
The side effect of huge size difference during upgrade is more stable
and convenient testing of "disk full" and "usb unplug" cases.

More detailed description is available here:
https://phabricator.apertis.org/T5439#189061



Signed-off-by: Denis Pynkin <denis.pynkin@collabora.com>