Teach apps to refresh AppInfos without restarting

Teach running applications to refresh already loaded ApplicationInfo
objects without resorting to restarting the application process.

Activities will be scheduled for restart via the regular life-cycle.
This is similar to a configuration change but since ApplicationInfo
changes are too low-level we don't permit apps to opt out.

This change is intended to be used with runtime resource overlays and
split APKs.

Test: Manual - command to update application via ActivityManagerShellCommand
Change-Id: Ice10a1691cced90eee95e3278fd784b8a9206d87