Implement issue #16330060: Inform ActivityManager about WebView...

...state changes.

Add a new API to tell the activity manager about a new dependency
one process has on another package.  Start using it already for
when apps is Context.createPackageContext() to load code from another
app.

Also do some work on getting the monitoring of proc/uid states
in shape so it can be used by unundled code, along with an
AppImportanceMonitor class for doing so.

Some small fixes and additions to VoiceInteractionService.

Improve handling of unaccounted/overcounted battery use so that
they aren't shown to the user unless they are significant.

Change-Id: I22dd79a73f4e70103d3f8964494aebc8a31f971c