finalize: do battery cutoff when reboot

Now we have new method to do battery cutoff when reboot. This CL
removes 'battery_cutoff_at_shutdown', and add an additional check on the
support of the image before in-place wipe.

BUG=chromium:601705
TEST=Manually on Chell

CQ-DEPEND=CL:344434

Change-Id: I830803376713aba683d88072504608d2b422d051
Reviewed-on: https://chromium-review.googlesource.com/344564
Commit-Ready: Shun-Hsing Ou <shunhsingou@chromium.org>
Tested-by: Shun-Hsing Ou <shunhsingou@chromium.org>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
diff --git a/py/gooftool/commands.py b/py/gooftool/commands.py
index 339eaa0..afd1ae2 100755
--- a/py/gooftool/commands.py
+++ b/py/gooftool/commands.py
@@ -682,7 +682,7 @@
     '--cutoff_args',
     help='Battery cutoff arguments to be passed to battery_cutoff.sh '
          'after wiping. Should be the following format: '
-         '[--method shutdown|reboot|battery_cutoff|battery_cutoff_at_shutdown] '
+         '[--method shutdown|reboot|battery_cutoff] '
          '[--check-ac connect_ac|remove_ac] '
          '[--min-battery-percent <minimum battery percentage>] '
          '[--max-battery-percent <maximum battery percentage>] '