[linux] Extended the lifetime of the ozone-platform-hint flag.

The flag is meant to help the Linux users until the Wayland platform is
finally released and Chromium has some stable way to select the backend.

This patch prolongs the lifetime to five milestones more, to M120.

Bug: 1246928, 1440398
Change-Id: If27d5bffb6a598aa925b57df9ff87014d3fb80ad
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4487854
Auto-Submit: Alexander Dunaev <adunaev@igalia.com>
Reviewed-by: Maksim Sisov <msisov@igalia.com>
Commit-Queue: Thomas Anderson <thomasanderson@chromium.org>
Reviewed-by: Thomas Anderson <thomasanderson@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1137216}
diff --git a/chrome/browser/flag-metadata.json b/chrome/browser/flag-metadata.json
index 63bc38ff..840b43e 100644
--- a/chrome/browser/flag-metadata.json
+++ b/chrome/browser/flag-metadata.json
@@ -5932,7 +5932,7 @@
     // chrome://flags.  See https://crbug.com/1246928.
     "name": "ozone-platform-hint",
     "owners": [ "rjkroege", "thomasanderson", "msisov@igalia.com", "nickdiego@igalia.com", "adunaev@igalia.com" ],
-    "expiry_milestone": 115
+    "expiry_milestone": 120
   },
   {
     "name": "page-content-annotations",