Fix issue #21816660 (app standby), work on issue #20882522 (voice interact)

Issue #21816660: More app standby abuse prevention

We now apply the same rules for deciding when an app has counted
as active when the screen is on as when the screen is off; the only
change this really means is that we don't immediately count foreground
services as making an app active both screen on as well as the
existing behavior for screen off.

Also small fix to how we switch into voice interaction mode that
guarantees we immediately switch to the screen on state.

Issue #20882522 VI: voice interactor service not restarted

This fixes some problems in the framework, allowing it to be
correctly restarted (and rolled by to the default voice interactor
if appropriate).  There are still some problems in system UI that
leave things broken in some cases.

Also small fix to how we switch into voice interaction mode that
guarantees we immediately switch to the screen on state.

Change-Id: Ie4fd098a2f5174a2c94f36d30427fb2a9db3d835