blink: Update OWNERS file for ImageBitmap

TBR=fserb@chromium.org

Change-Id: I05a35c241e4f9793675c6a56e38362928ce831b2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2001292Reviewed-by: Khushal <khushalsagar@chromium.org>
Reviewed-by: Fernando Serboncini <fserb@chromium.org>
Commit-Queue: Khushal <khushalsagar@chromium.org>
Cr-Commit-Position: refs/heads/master@{#732574}

third_party/blink/renderer/core/imagebitmap/OWNERS

 fserb@chromium.org
-zakerinasab@chromium.org
 
 # TEAM: paint-dev@chromium.org
 # COMPONENT: Blink>Canvas