Chrome OS Settings: Move set-pin keyboard element to cr_components.

This CL extracts PIN-setting element into cr_components so that it could be
integrated into another WebUI.

Bug: 852553
Change-Id: Ia7e08465fbaf5d457f1d804dbfc2dbba2e6a5071
Reviewed-on: https://chromium-review.googlesource.com/1212404
Commit-Queue: Alexander Alekseev <alemate@chromium.org>
Reviewed-by: Michael Giuffrida <michaelpg@chromium.org>
Cr-Commit-Position: refs/heads/master@{#589748}
14 files changed