Make RegisteredServicesCache understand ASEC-based updates

Specifically, when the ASEC container has been unmounted as part
of updating the app we mustn't immediately conclude that any
services hosted there have become invalid until after we see the
matching remount result and have a chance to re-evaluate in the
proper new state.

Bug 12422464

Change-Id: I27794c6e4348f6a72d64bd2f44b4da7938cc567b