Add back privacy chip

This adds back the privacy chip classes (Controller and view).

Change to using Executors and DeviceConfigProxy, also fix tests that
were flaky before.

Test: SystemUITests
Bug: 160966908
Change-Id: Id3e5981a87c33a8cabe7ce348f9512d81ad2b1d8
Merged-In: Id3e5981a87c33a8cabe7ce348f9512d81ad2b1d8