[Android] Update OWNERS information (ar)

https://docs.google.com/document/d/1SWAM_6e1Tk4UexJ1QuZJUtfXCQEqRfAQT_mfkSqBJqM

Bug: 1112872
Change-Id: I387fb3f0f7d96b0dc92cd5494668b29735d870e0
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2339925
Auto-Submit: Fred Mello <fredmello@chromium.org>
Reviewed-by: Ian Vollick <vollick@chromium.org>
Commit-Queue: Ian Vollick <vollick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#795166}

chrome/android/features/ar/OWNERS

-vollick@chromium.org
+file://chrome/android/features/vr/OWNERS
 
 # TEAM: xr-dev@chromium.org
 # COMPONENT: Internals>XR>AR