installer: force updating firmware in factory install mode.

Factory test images (and install shims) are configured with
"leave_firmware_alone" because they may contain firmware blobs that are
different from the real version to install.

So we have to explicitly assign the "force" flag when factory installer is
trying to update the firmware to the assigned version (by make_factory_package
--firmwareupdate).

BUG=chrome-os-partner:3152
TEST=none, will be updated before commiting

Change-Id: I449de11cb1785fd69890527313fbdce18f8b835f

R=wfrichar@chromium.org,rspangler@chromium.org

Review URL: http://codereview.chromium.org/6795002
1 file changed