Extend flag ios-popular-sites-improved-suggestions to M118.

(cherry picked from commit 2bc1808)

Bug: 1420295
Change-Id: I5f6d62629fa735a751dc0a6697cdc8b6d0f2368c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4295140
Reviewed-by: Scott Yoder <scottyoder@google.com>
Commit-Queue: Benjamin Williams <bwwilliams@google.com>
Cr-Original-Commit-Position: refs/heads/main@{#1111041}
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4298230
Cr-Commit-Position: refs/branch-heads/5615@{#68}
Cr-Branched-From: 9c6408e-refs/heads/main@{#1109224}

chrome/browser/flag-metadata.json

@@ -4471,7 +4471,7 @@
   },  {
     "name": "ios-popular-sites-improved-suggestions",
     "owners": ["bwwilliams@google.com", "bling-flags@google.com"],
-    "expiry_milestone": 112
+    "expiry_milestone": 118
   },
   {
     "name": "ios-shared-highlighting-color-change",