[Passwords] Add stubs for native Password Checkup on Android

This change adds stubs for integrating the native Password Checkup on
Android for the Leak Detection feature.

Bug: 986317
Change-Id: Idf57d8a812ee11e6d862dbd68ecb54ea58aff738
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1773221
Reviewed-by: Ioana Pandele <ioanap@chromium.org>
Commit-Queue: Jan Wilken Dörrie <jdoerrie@chromium.org>
Cr-Commit-Position: refs/heads/master@{#691036}
2 files changed