Don't use restricted backup launch mode for system-ish processes

We now impose restricted launch behavior and lifetime only on "ordinary"
apps' backup/restore operations.  System-ish targets such as the telephony
provider continue to get their full Application instance and providers,
and won't get killed following conclusion of the data-moving operations.
Such customers of backup/restore are expected to be able to deal
gracefully with this sort of thing.

Bug 27362301
Bug 27076602

Change-Id: Ib62483b8469cc750a20f80b7c596ad486a397564