Add myself to Switch Access OWNERS

NOTRY=true

Bug: None
Change-Id: Ie43aeaedeb728f9c1a191ed988922cedcc2cc238
Reviewed-on: https://chromium-review.googlesource.com/c/1347611Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Commit-Queue: Dominic Mazzoni <dmazzoni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#610895}

chrome/browser/resources/chromeos/switch_access/OWNERS

 file://ui/accessibility/OWNERS
+anastasi@google.com
 
 # TEAM: chromium-accessibility@chromium.org
 # COMPONENT: UI>Accessibility