Extend Auto Select flag expiration

Extend the expiry milestone of AutoSelet chrome flag which is still in use.

Bug: None
Test: Locally build and test
Change-Id: I9f36f407f80812b5109db8297d4fb990817c54aa
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2574075Reviewed-by: Xiaohui Chen <xiaohuic@chromium.org>
Commit-Queue: Yue Li <updowndota@chromium.org>
Cr-Commit-Position: refs/heads/master@{#833939}

chrome/browser/flag-metadata.json

@@ -1240,7 +1240,7 @@
   {
     "name": "enable-auto-select",
     "owners": ["croissant-eng"],
-    "expiry_milestone": 88
+    "expiry_milestone": 90
   },
   {
     "name": "enable-autofill-account-wallet-storage",