Delay expiry of frequently used histograms.

Updates the expires_after attribute for 102 histograms that show
frequent access in the past 90 days.  These are the 90% most
frequently used histograms over that time that do not already
have a date later than or within 60 days of 2020-11-23.

TBR=chromium-metrics-reviews@google.com

Change-Id: Ib7784db31c75622a48f6365cb8c2f49b1e1ea0c6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2374934Reviewed-by: Chrome Metrics Logs <chrome-metrics-team+robot@google.com>
Reviewed-by: Brian White <bcwhite@chromium.org>
Commit-Queue: Chrome Metrics Logs <chrome-metrics-team+robot@google.com>
Commit-Queue: Brian White <bcwhite@chromium.org>
Cr-Commit-Position: refs/heads/master@{#801538}

tools/metrics/histograms/histograms_xml/UMA/histograms.xml

@@ -529,7 +529,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="UMA.TruncatedEvents.UserAction" units="events"
-    expires_after="2021-01-31">
+    expires_after="2021-02-21">
   <owner>rkaplow@chromium.org</owner>
   <owner>src/base/metrics/OWNERS</owner>
   <summary>