Delay expiry of frequently used histograms.

Updates the expires_after attribute for 513 histograms that show
frequent access in the past 90 days.  These are the 95% most
frequently used histograms over that time that do not already
have a date later than or within 60 days of 2021-03-08.

TBR=chromium-metrics-reviews@google.com

Change-Id: Idd8494417ce75b3f0196fe29cc5e319908f4d763
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2579445


Reviewed-by: Chrome Metrics Logs <chrome-metrics-team+robot@google.com>
Commit-Queue: Chrome Metrics Logs <chrome-metrics-team+robot@google.com>
Cr-Commit-Position: refs/heads/master@{#834809}