aw: Add vasilyt to gfx owners

Also remove ericrk who has unfortunately left the chromium project.

Change-Id: I7184d88d6cec1c264760d2c01e1301913d43c399
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2042289
Auto-Submit: Bo <boliu@chromium.org>
Reviewed-by: Vasiliy Telezhnikov <vasilyt@chromium.org>
Commit-Queue: Vasiliy Telezhnikov <vasilyt@chromium.org>
Cr-Commit-Position: refs/heads/master@{#739381}

android_webview/browser/gfx/OWNERS

 boliu@chromium.org
-ericrk@chromium.org
+vasilyt@chromium.org