[autotest] Add script for finding hosts with high reboot times

This script queries metadata db for reboot times within a certain time
range and prints the hosts and reboot times in descending order.

BUG=None
TEST=python analyze_reboot_time.py -l 12 --server cautotest --pool bvt

Change-Id: Id144d5ec8968bc18979a363d2f16365f795d2fc6
Reviewed-on: https://chromium-review.googlesource.com/210694
Reviewed-by: Dan Shi <dshi@chromium.org>
Tested-by: Michael Liang <michaelliang@chromium.org>
Commit-Queue: Michael Liang <michaelliang@chromium.org>
1 file changed