[Lens]Extend image format optimizations flag expiry

Bug: b/295210784
Change-Id: I6ac70cb5966f693f80b01de9594bd065b0e431f0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4769606
Reviewed-by: Duncan Mercer <mercerd@google.com>
Commit-Queue: Jason Hu <hujasonx@google.com>
Cr-Commit-Position: refs/heads/main@{#1182169}

chrome/browser/flag-metadata.json

@@ -3003,7 +3003,7 @@
   {
     "name": "enable-lens-image-format-optimizations",
     "owners": ["mercerd@google.com", "stanfield@google.com", "lens-chrome@google.com"],
-    "expiry_milestone": 116
+    "expiry_milestone": 120
   },
   {
     "name": "enable-lens-image-translate",