Update expiring histograms

Extend the expiration date and update the ownership for the following
histograms:
* ManagedUsers.SafeSitesDelay*
* Supervision.ParentAccessCode*

Bug: 1138331, 1138414
Change-Id: Icdec80809c3195a20ed64c7ca1076d22ff8012c3
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2471218
Reviewed-by: Tarun Bansal <tbansal@chromium.org>
Commit-Queue: Aga Wronska <agawronska@chromium.org>
Cr-Commit-Position: refs/heads/master@{#818097}

tools/metrics/histograms/histograms_xml/others/histograms.xml

@@ -8249,9 +8249,9 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="ManagedUsers.SafeSitesDelay" units="ms"
-    expires_after="2020-11-20">
+    expires_after="2021-10-15">
   <owner>agawronska@chromium.org</owner>
-  <owner>cros-families@google.com</owner>
+  <owner>cros-families-eng@google.com</owner>
   <summary>
     The extra page load delays introduced by network requests due to the
     supervised user SafeSites feature, measured once per page load.
@@ -14319,19 +14319,19 @@ should be kept until we remove incident reporting. -->
 </histogram>
 
 <histogram name="Supervision.ParentAccessCode.Action"
-    enum="ParentAccessCodeAction" expires_after="M88">
+    enum="ParentAccessCodeAction" expires_after="2021-10-15">
   <owner>agawronska@chromium.org</owner>
-  <owner>cros-families@google.com</owner>
+  <owner>cros-families-eng@google.com</owner>
   <summary>
     Action originated in parent access code dialog. Logged every time the action
     happens.
   </summary>
 </histogram>
 
 <histogram name="Supervision.ParentAccessCode.Usage"
-    enum="ParentAccessCodeUsage" expires_after="M88">
+    enum="ParentAccessCodeUsage" expires_after="2021-10-15">
   <owner>agawronska@chromium.org</owner>
-  <owner>cros-families@google.com</owner>
+  <owner>cros-families-eng@google.com</owner>
   <summary>
     The context in which parent access code was used. Logged every time the new
     parent access dialog is shown.