Transferring Android Selection ownership to Shimi

I'm leaving Chrome and am transferring my Android Selection ownership
to Shimi.

Change-Id: I9dd6aa1d5837ce8bd17d1bbaa9bdb750bb1bef6c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1644378Reviewed-by: Shimi Zhang <ctzsm@chromium.org>
Commit-Queue: Pedro Amaral <amaralp@chromium.org>
Cr-Commit-Position: refs/heads/master@{#666072}

content/browser/android/selection/OWNERS

-amaralp@chromium.org
+ctzsm@chromium.org

content/public/android/java/src/org/chromium/content/browser/selection/OWNERS

-amaralp@chromium.org
+ctzsm@chromium.org

content/public/android/junit/src/org/chromium/content/browser/selection/OWNERS

-amaralp@chromium.org
+ctzsm@chromium.org