Update expiry of Sync.KeystoreDecryptionFailed

Bug: 1138388
Change-Id: I49409684460a7890b8f82547d1b887c76e676ecc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2532077
Auto-Submit: Maksim Moskvitin <mmoskvitin@google.com>
Commit-Queue: Jesse Doherty <jwd@chromium.org>
Reviewed-by: Jesse Doherty <jwd@chromium.org>
Cr-Commit-Position: refs/heads/master@{#826776}

tools/metrics/histograms/histograms_xml/sync/histograms.xml

@@ -413,9 +413,9 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="Sync.KeystoreDecryptionFailed"
-    enum="SyncKeystoreDecryptionFailure" expires_after="2020-11-15">
+    enum="SyncKeystoreDecryptionFailure" expires_after="2021-06-01">
+  <owner>mmoskvitin@google.com</owner>
   <owner>mastiz@chromium.org</owner>
-  <owner>treib@chromium.org</owner>
   <summary>
     The reason for a failure decrypting the keystore decryptor token.
   </summary>