Add multi-user support to Controls

This commit adds multi-user support by doing the following:
* Listening when user changes and switching the controllers user (and
context).
* Using activities that show for all users and are finished on user
switched.

The setting has to be enabled for each user separately.

Also:
* fixes calling subscribe when on load to the ControlsProviderService.
* better dumps.

Test: atest
Test: check that files are not shared between users
Test: check that user folder is removed when user is deleted
Bug:147732882
Change-Id: I349b0136473016e6bd6b71e26045f11a839272d1