Add full backup criteria to android manifest

BUG: 20010079
Api change: ApplicationInfo now has a fullBackupContent int
where -1 is (off) 0 is (on) and >0 indicates an xml
resource that should be parsed in order for a developer
to indicate exactly which files they want to include/exclude
from the backup set.
dd: https://docs.google.com/document/d/1dnNctwhWOI-_qtZ7I3iNRtrbShmERj2GFTzwV4xXtOk/edit#heading=h.wcfw1q2pbmae

Change-Id: I90273dc0aef5e9a3230c6b074a45e8f5409ed5ce