Revert^2 "[keystore2] Fix binder import path"

Import from the binder crate root instead of binder::public_api for
compatibility with the new crate structure.

Original change: Ia9695e5493bda965ca9a42989ec5a284407595ce

Test: m
Bug: 196056781

Change-Id: Ie6303a36a956cf73f317520a0e0a00ec4adbb47e
11 files changed