Reland WebAPK Site Settings Shortcut using startActivityForResult.

Bug: 1138210
Change-Id: I95d57fb3fe0802298fad44d4415aaac7e87871bd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2510250


Reviewed-by: Peter Conn <peconn@chromium.org>
Reviewed-by: Yaron Friedman <yfriedman@chromium.org>
Commit-Queue: Michael van Ouwerkerk <mvanouwerkerk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#824882}