Add aliceywang@ as owner of /chrome/browser/android/signin

Bug: None
Change-Id: I229c095171cbea3f2f325f93752dee885e4842d4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2627856
Auto-Submit: Alice Wang <aliceywang@chromium.org>
Commit-Queue: Mihai Sardarescu <msarda@chromium.org>
Reviewed-by: Mihai Sardarescu <msarda@chromium.org>
Cr-Commit-Position: refs/heads/master@{#843517}

chrome/browser/android/signin/OWNERS

 bsazonov@chromium.org
+aliceywang@chromium.org