When aapt sees @SystemApi in the XML comment associated with a resource,
it will now remove this tag from the comment (since is it not meaningful as
a Javadoc tag) and instead add an @android.annotation.SystemApi annotation
to the declared type or member. This enables easy downstream processing of
this annotation from generated code.
Change-Id: If984908477648c0c90be52fdc955fbb891d99b28
709ce0a4c6