Extend the SendFeedback histogram for another year, we are still using it.

Bug: 1160725
Change-Id: I5f90794fbeadc3799c40b87388f46e7ba8221c53
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2643701Reviewed-by: Carlos Knippschild <carlosk@chromium.org>
Reviewed-by: Alexei Svitkine <asvitkine@chromium.org>
Commit-Queue: Peter Williamson <petewil@chromium.org>
Cr-Commit-Position: refs/heads/master@{#846219}

tools/metrics/histograms/histograms_xml/content/histograms.xml

@@ -1158,7 +1158,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="ContentSuggestions.Feed.SendFeedback"
-    enum="FeedSendFeedbackType" expires_after="2021-02-01">
+    enum="FeedSendFeedbackType" expires_after="2022-02-01">
   <owner>carlosk@chromium.org</owner>
   <owner>petewil@chromium.org</owner>
   <owner>feed@chromium.org</owner>