* Put in some permission enforcement around agent connection notification
and full-backup scheduling.
* Full backup now applies to any package, not just backup participants who
have declared their own android:backupAgent
* The process of running the backup operation on the set of apps who have
been queued for it is now done in a separate thread, with a notification
mechanism from the main Backup Manager service to pass along new-agent
binding knowledge. There's no longer one do-backup message on the primary
Handler per target application.
* The new backup thread sets up the desired transport now and passes
along the newly backed-up data to it for each backup target. Two
transports have been defined so far, GoogleTransport and AdbTransport;
both are stubs at present.
Note that at present the backup data output file seems to be properly
created, but after doBackup() is called on the test app's agent it's
still zero size.