Update Android SDK and Android System SDK to S.

Switch to the S SDK and system SDK, and add the WebView code to support
WebView S APIs.

Bug: 1223110
Change-Id: Ice272cdcc313cfd9f2845fa66a59d7c99e974314
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3032285
Reviewed-by: Ted Choc <tedchoc@chromium.org>
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Commit-Queue: Richard Coles <torne@chromium.org>
Cr-Commit-Position: refs/heads/master@{#904462}
NOKEYCHECK=True
GitOrigin-RevId: 1d710546a79dcb311c095083506f41daa626aff5