Extend 'enterprise-reporting-in-chromeos' flag to M87

Change-Id: Iba122adad93174ea75504d15c53cc9c9795ab52c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2246512Reviewed-by: Owen Min <zmin@chromium.org>
Commit-Queue: Anqing Zhao <anqing@chromium.org>
Cr-Commit-Position: refs/heads/master@{#778495}

chrome/browser/flag-metadata.json

@@ -2477,7 +2477,7 @@
   {
     "name": "enterprise-reporting-in-chromeos",
     "owners": [ "anqing" ],
-    "expiry_milestone": 83
+    "expiry_milestone": 87
   },
   {
     "name": "ev-details-in-page-info",