factory: Complete shopfloor and connect to factory_Start.

This CL puts everything together so that factory test images can now communicate
with shop floor server (for factory_Start).

BUG=chrome-os-partner:6911
TEST=manually.
     (1) Run shop floor server: shopfloor_server -m shopfloor.sample.SampleShopFloor
     (2) Run factory installation process by install shim
     (3) Modify test list to enable shop floor (_ENABLE_SHOP_FLOOR=True)
     (4) Start factory test image
     (5) Enter "abc" as serial number - rejected as invalid input
     (6) Enter "0123" as serial number - accepted and continued to next test.

Change-Id: I7d98e4cd381fa8b23d2f36a216fd804c9171020f
Reviewed-on: https://gerrit.chromium.org/gerrit/16125
Reviewed-by: Jon Salz <jsalz@chromium.org>
Commit-Ready: Hung-Te Lin <hungte@chromium.org>
Tested-by: Hung-Te Lin <hungte@chromium.org>
4 files changed