Extend expiry of scrollable shelf drag histograms

Bug: 1138409, 1138410
Change-Id: Idab54cc099b32a514678378e83a0dafa200352c9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2511031
Commit-Queue: Ana Salazar <anasalazar@chromium.org>
Commit-Queue: Alexei Svitkine <asvitkine@chromium.org>
Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
Cr-Commit-Position: refs/heads/master@{#822798}

tools/metrics/histograms/histograms_xml/apps/histograms.xml

@@ -1714,7 +1714,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 
 <histogram base="true"
     name="Apps.ScrollableShelf.Drag.PresentationTime.MaxLatency" units="ms"
-    expires_after="2020-11-08">
+    expires_after="2021-11-08">
 <!-- Name completed by histogram_suffixes
      name="TabletOrClamshellMode" and
      name="HomeLauncherVisibility" -->