Extend Sync.ConflictResolution to M82

It's still useful, see e.g. crbug.com/1021537

Bug: 1021168
Change-Id: I4f870f93c65532277763fb5dab1eb3096f5ea680
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1899846
Auto-Submit: Marc Treib <treib@chromium.org>
Reviewed-by: Brian White <bcwhite@chromium.org>
Commit-Queue: Brian White <bcwhite@chromium.org>
Cr-Commit-Position: refs/heads/master@{#712733}
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index a319a6e..3555eed 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -146838,7 +146838,7 @@
 </histogram>
 
 <histogram name="Sync.ResolveConflict" enum="SyncConflictResolutions"
-    expires_after="M80">
+    expires_after="M82">
   <owner>treib@chromium.org</owner>
   <owner>mastiz@chromium.org</owner>
   <summary>