Upload command stats in image_to_live.sh

We want to keep track of the usage of the script.

BUG=chromium:350187
TEST=Ran image_to_live.sh and view the stats

Change-Id: I6d25a330ca40355147133ddd5a196ffab65ecbde
Reviewed-on: https://chromium-review.googlesource.com/189490
Reviewed-by: Chris Sosa <sosa@chromium.org>
Commit-Queue: Yu-Ju Hong <yjhong@chromium.org>
Tested-by: Yu-Ju Hong <yjhong@chromium.org>
diff --git a/host/image_to_live.sh b/host/image_to_live.sh
index 7bea903..3721575 100755
--- a/host/image_to_live.sh
+++ b/host/image_to_live.sh
@@ -565,6 +565,7 @@
     fi
   done
 
+  command_completed
   exit 0
 }