Change expire_milestone for cookie_controls flags

The feature is not fully launched yet, so increasing expire_milestone.

Change-Id: I287aef3827babdeb33849670dd6dc7ec07f4e282
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2154799
Auto-Submit: Christian Dullweber <dullweber@chromium.org>
Reviewed-by: Ehimare Okoyomon <eokoyomon@chromium.org>
Commit-Queue: Christian Dullweber <dullweber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#760479}

chrome/browser/flag-metadata.json

@@ -2637,12 +2637,12 @@
   {
     "name": "improved-cookie-controls",
     "owners": [ "dullweber", "huanzhong" ],
-    "expiry_milestone": 84
+    "expiry_milestone": 86
   },
   {
     "name": "improved-cookie-controls-for-third-party-cookie-blocking",
     "owners": [ "dullweber", "huanzhong" ],
-    "expiry_milestone": 84
+    "expiry_milestone": 86
   },
   {
     "name": "impulse-scroll-animations",