[Extensions] Extend histogram's lifetime

This commit moves expire date of the following histograms:
 * Extensions.ForceInstalledManifestFetchFailedHttpErrorCode2
 * Extensions.ForceInstalledReadyTime
 * Extensions.ForceInstalledStage2

The expire date is now in sync with other histograms owned by our team
(Extensions.Force*).

Bug: 1165254, 1165255
Change-Id: Ie7d7ce0e96fe813321f7dbab53b1667bdf82bc4c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2642366
Auto-Submit: Oleg Davydov <burunduk@chromium.org>
Commit-Queue: Robert Kaplow <rkaplow@chromium.org>
Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#845637}

tools/metrics/histograms/histograms_xml/extensions/histograms.xml

@@ -1575,7 +1575,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="Extensions.ForceInstalledManifestFetchFailedHttpErrorCode2"
-    enum="HttpResponseCode" expires_after="2021-01-24">
+    enum="HttpResponseCode" expires_after="2021-05-30">
   <owner>burunduk@chromium.org</owner>
   <owner>swapnilgupta@google.com</owner>
   <owner>managed-devices@google.com</owner>
@@ -1634,7 +1634,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="Extensions.ForceInstalledReadyTime" units="ms"
-    expires_after="2021-01-24">
+    expires_after="2021-05-30">
   <owner>snijhara@google.com</owner>
   <owner>burunduk@chromium.org</owner>
   <owner>swapnilgupta@google.com</owner>
@@ -1663,7 +1663,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="Extensions.ForceInstalledStage2"
-    enum="ExtensionInstallationStage" expires_after="2021-01-24">
+    enum="ExtensionInstallationStage" expires_after="2021-05-30">
   <owner>burunduk@chromium.org</owner>
   <owner>swapnilgupta@google.com</owner>
   <owner>managed-devices@google.com</owner>