[autotest] Modify dhcp diagnosis script to detect dhcpd restarts.

TEST=Ran the script.
BUG=None

Change-Id: If3948b96992c9ce529824aea27ba33d23c82a0a1
Reviewed-on: https://chromium-review.googlesource.com/202639
Reviewed-by: Prashanth B <beeps@chromium.org>
Commit-Queue: Prashanth B <beeps@chromium.org>
Tested-by: Prashanth B <beeps@chromium.org>
1 file changed