flags: Renew CrOS image decode acceleration flags.

This CL renews the "enable-vaapi-jpeg-image-decode-acceleration" and
"enable-vaapi-webp-image-decode-acceleration" flags which are still
useful to experiment with the JPEG and WebP hardware decode path in
Chrome OS (not launched yet).

Bug: None.
Test: None.
Change-Id: Id314de274805667c05c5d340a58c0e0ad254be25
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2367733Reviewed-by: Andres Calderon Jaramillo <andrescj@chromium.org>
Reviewed-by: Gil Dekel <gildekel@chromium.org>
Commit-Queue: Andres Calderon Jaramillo <andrescj@chromium.org>
Cr-Commit-Position: refs/heads/master@{#800315}

chrome/browser/flag-metadata.json

@@ -2229,13 +2229,13 @@
   },
   {
     "name": "enable-vaapi-jpeg-image-decode-acceleration",
-    "owners": [ "chromeos-gfx@google.com" ],
-    "expiry_milestone": 83
+    "owners": [ "andrescj", "chromeos-gfx@google.com" ],
+    "expiry_milestone": 90
   },
   {
     "name": "enable-vaapi-webp-image-decode-acceleration",
-    "owners": [ "chromeos-gfx@google.com" ],
-    "expiry_milestone": 83
+    "owners": [ "andrescj", "chromeos-gfx@google.com" ],
+    "expiry_milestone": 90
   },
   {
     "name": "enable-virtual-keyboard",