factory_installer: force updating firmware in factory install mode. (TBR)

factory_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=built a factory install shim, then
     make_factory_package --... --firmware_updater=xxx,
     and see firmware update messages on verbose progress log.

Change-Id: I913957e0abd2acdd1191f5c4c98c352eed50bf95

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

Committed: http://chrome-svn/viewvc/chromeos?view=rev&revision=eae040d

[Bill Richardson, 2011-04-07 16:08:05]

LGTM

[Randall Spangler, 2011-04-07 20:41:29]

LGTM