Add support for the libcore UnsupportedAppUsage annotation to
UnsupportedAppUsageProcessor. This is in order to make the two
annotations even more interchangeable.
Also take the opportunity to correct the documentation:
UnsupportedAppUsageProcessor no longer is involved in creating
greylist.txt, that functionality has been moved to
Class2Greylist.java in the art repository.
Bug: 130721457
Test: m framework-annotation-proc
Change-Id: I5cf1f97ca41349fc053315a2fd5bfd53a80ae128
5e22614098