[Android][Signin] Add aliceywang@ as owners of signin test files

Change-Id: Ibfe843de433b14191429389ecd601805f9d644cb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2069543Reviewed-by: Boris Sazonov <bsazonov@chromium.org>
Commit-Queue: Alice Wang <aliceywang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#745026}

chrome/android/javatests/src/org/chromium/chrome/browser/signin/OWNERS

 file://chrome/android/java/src/org/chromium/chrome/browser/signin/OWNERS
+aliceywang@chromium.org
 
 # COMPONENT: Services>Signin

chrome/android/junit/src/org/chromium/chrome/browser/signin/OWNERS

 file://chrome/android/java/src/org/chromium/chrome/browser/signin/OWNERS
+aliceywang@chromium.org
 
 # COMPONENT: Services>Signin