Extend the lifetime of the enable-quic flag.

Change-Id: Ia5780557422a98e990a188e6b538309c31d8dbf2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1810771
Commit-Queue: Ryan Hamilton <rch@chromium.org>
Reviewed-by: Elly Fong-Jones <ellyjones@chromium.org>
Cr-Commit-Position: refs/heads/master@{#697726}

chrome/browser/flag-metadata.json

@@ -1525,8 +1525,8 @@
   },
   {
     "name": "enable-quic",
-    "owners": [ "rch" ],
-    "expiry_milestone": 78
+    "owners": [ "//net/quic/OWNERS" ],
+    "expiry_milestone": 88
   },
   {
     "name": "enable-reader-mode",