CORS: Extends Net.Cors.* metrics expiry date

As we still have a plan to change CORS related minor behaviors,
we keep Net.Cors.* metrics until the next change is safely
launched.

Bug: 1104952
Change-Id: I6aa219981846f5a6a78c298d8ac121318ffb453f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2532144
Auto-Submit: Takashi Toyoshima <toyoshim@chromium.org>
Commit-Queue: David Schinazi <dschinazi@chromium.org>
Reviewed-by: David Schinazi <dschinazi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#826802}

tools/metrics/histograms/histograms_xml/net/histograms.xml

@@ -394,7 +394,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="Net.Cors.AccessCheckError" enum="CorsAccessCheckError"
-    expires_after="M86">
+    expires_after="M90">
   <owner>toyoshim@chromium.org</owner>
   <owner>yhirano@chromium.org</owner>
   <summary>
@@ -405,7 +405,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="Net.Cors.AccessCheckResult" enum="CorsAccessCheckResult"
-    expires_after="M86">
+    expires_after="M90">
   <owner>toyoshim@chromium.org</owner>
   <owner>yhirano@chromium.org</owner>
   <summary>
@@ -415,7 +415,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="Net.Cors.PreflightCacheKeySize" units="bytes"
-    expires_after="M86">
+    expires_after="M90">
   <owner>toyoshim@chromium.org</owner>
   <owner>yhirano@chromium.org</owner>
   <summary>
@@ -425,7 +425,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="Net.Cors.PreflightCacheResult" enum="CorsPreflightCacheResult"
-    expires_after="M86">
+    expires_after="M90">
   <owner>toyoshim@chromium.org</owner>
   <owner>yhirano@chromium.org</owner>
   <summary>
@@ -435,7 +435,7 @@ reviews. Googlers can read more about this at go/gwsq-gerrit.
 </histogram>
 
 <histogram name="Net.Cors.PreflightCheckError" enum="CorsAccessCheckError"
-    expires_after="M86">
+    expires_after="M90">
   <owner>toyoshim@chromium.org</owner>
   <owner>yhirano@chromium.org</owner>
   <summary>