Extend flag enable-autofill-account-wallet-storage to M83

Bug: 983940
Change-Id: Ie46727c855e23f5c8f4b33767275fd2c97ea436c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2010798
Auto-Submit: Marc Treib <treib@chromium.org>
Reviewed-by: Jared Saul <jsaul@google.com>
Commit-Queue: Jared Saul <jsaul@google.com>
Cr-Commit-Position: refs/heads/master@{#733725}

chrome/browser/flag-metadata.json

@@ -1015,7 +1015,7 @@
   {
     "name": "enable-autofill-account-wallet-storage",
     "owners": [ "treib", "jsaul@google.com", "butter-team@google.com" ],
-    "expiry_milestone": 81
+    "expiry_milestone": 83
   },
   {
     "name": "enable-autofill-credit-card-ablation-experiment",