Use framework-annotation-libs for hwbinder-stubs-docs

hwbinder.stubs and hwbinder-stubs-docs use SystemApi annotations.
Provide an explicit definition of SystemApi to metalava by adding
framework-annotations-libs to libs so it doesn't find it on its
own without a dependency.  Replace stub-annotations with
framework-annotations-libs in hwbinder.stubs for consistency.

Bug: 153703940
Test: m hwbinder.stubs
Change-Id: I777d68e446f8c7c1064667fd7c07b1e2ee6bfb1b