[autotest] Add provisioning job provision_FirmwareUpdate

This CL adds site_tests/provision_FirmwareUpdate which provisions a
system to the correct firmware version.
It also updates provision.py to map fw-version label to the right
provisioning job.

BUG=chromium:250585
TEST=1) Ran the control segment manually via
|./server/autoserv server/control_segments/provision --args
"fw-version:link-firmware/R22-2695.1.144" -m MY_DUT_IP|, and confirmed
the provision_FirmwareUpdate test was invoked and passed.
2) Ran the control file of the test via
|./server/autoserv server/site_tests/provision_FirmwareUpdate/control
--args value=link-firmware/R22-2695.1.144 servo_host=MY_SERVO_IP
-m MY_DUT_IP|, and confirmed the test passed.
3) Ran ./site_utils/run_suite.py -b link -i link-release/R30-4537.0.0
-s faft_dev -f False. Confirmed firmware update provisioning job
is scheduled.
DEPLOY=scheduler

Change-Id: Id68a628106495155c74ef6d525eed93eeda09f07
Reviewed-on: https://gerrit.chromium.org/gerrit/65399
Reviewed-by: Alex Miller <milleral@chromium.org>
Commit-Queue: Fang Deng <fdeng@chromium.org>
Tested-by: Fang Deng <fdeng@chromium.org>
3 files changed