crash-reporter: Include powerd logs with crashes.

Attach relevant power manager logs to crash reports for
powerd, powerd_setuid_helper, and power_supply_info.

BUG=chromium:405727
TEST=induced crashes in powerd, powerd_setuid_helper, and
     power_supply_info, then forced crash reporting with
     "FORCE_OFFICIAL=1 crash_sender" and checked that the
     following crash reports had the expected data attached
     in the "Files" section:
     2f710954e30472b1 (powerd)
     e7d985b7dbd9d158 (powerd_setuid_helper)
     2213b0413fc9e408 (power_supply_info)

Change-Id: Icddb7d0b99eb19b95c656f8c06d8766733eaae28
Reviewed-on: https://chromium-review.googlesource.com/216020


Tested-by: Daniel Erat <derat@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Daniel Erat <derat@chromium.org>