[Profile menu] Extend a histogram

This CL extends expiry for a histogram that will still be useful for
experimentation in a few following milestones.

Bug: 1117116
Change-Id: I4722a1452a92ceb99669b83735b542b0225f8b8b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2478602
Auto-Submit: Jan Krcal <jkrcal@chromium.org>
Reviewed-by: Weilun Shi <sweilun@chromium.org>
Reviewed-by: Brian White <bcwhite@chromium.org>
Commit-Queue: Brian White <bcwhite@chromium.org>
Cr-Commit-Position: refs/heads/master@{#818101}

tools/metrics/histograms/histograms_xml/profile/histograms.xml

@@ -235,7 +235,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="Profile.Menu.OpenedAfterAvatarAnimation" units="ms"
-    expires_after="2020-09-27">
+    expires_after="2021-04-15">
   <owner>droger@chromium.org</owner>
   <owner>jkrcal@chromium.org</owner>
   <summary>