Delay expiry of frequently used histograms.

Updates the expires_after attribute for 174 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 2021-04-05.

TBR=chromium-metrics-reviews@google.com

Change-Id: I011a2481967313e6d2e340a32bd1657850cd90e5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2611306


Reviewed-by: Chrome Metrics Logs <chrome-metrics-team+robot@google.com>
Reviewed-by: Caitlin Fischer <caitlinfischer@google.com>
Commit-Queue: Chrome Metrics Logs <chrome-metrics-team+robot@google.com>
Commit-Queue: Caitlin Fischer <caitlinfischer@google.com>
Cr-Commit-Position: refs/heads/master@{#840234}