Add a SoftwareReporter.RunningTimeWithoutSleep histogram

This will help estimate how much of the reported
SoftwareReporter.RunningTimeAccordingToChrome > 5 min is due to the
computer being asleep for 5+ min.

Also push back the expiry date of
SoftwareReporter.RunningTimeAccordingToChrome by 6 months since it's
proved useful in a bug investigation.

R=drubery

Bug: 1213207
Change-Id: I645b76b5ef6811be044c4f0f83703e586463b1d7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2929363
Auto-Submit: Joe Mason <joenotcharles@chromium.org>
Reviewed-by: Daniel Rubery <drubery@chromium.org>
Commit-Queue: Joe Mason <joenotcharles@chromium.org>
Cr-Commit-Position: refs/heads/master@{#889070}