[CrOS MultiDevice] Make AndroidSmsService own related classes.

This CL makes AndroidSmsService the owner of AndroidSmsAppHelperDelegate
and AndroidSmsPairingStateTracker (previously, objects of these classes
belonged to MultiDeviceSetupService). Upcoming changes require that
these classes be shared among multiple clients, so it is necessary that
they be accessible outside of the service.

As part of this change, I updated AndroidSmsService's constructor to
take other KeyedServices as explicit parameters to make dependencies
clear, and I updated its factory to depend on the other KeyedServices'
factories.

Bug: 918943, 876972
Change-Id: Iee064d97349bccb191533056ceea5cb52984dcba
Reviewed-on: https://chromium-review.googlesource.com/c/1402022
Commit-Queue: Kyle Horimoto <khorimoto@chromium.org>
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Reviewed-by: Stefan Kuhne <skuhne@chromium.org>
Cr-Commit-Position: refs/heads/master@{#621800}
31 files changed