Add RemoteFrameworkClasses.

This target generates pre-annotated interfaces of public + test APIs for
framework classes - based on the api txt files.

This requires manually copying api text files in - so that we don't
start failing to build blocking someone else's framework change. I'll
add a script to do this automatically in a later CL.

This will be followed by using this in TestApp to add support for using
system services from the test app.

Test: Building
Bug: 188894962
Change-Id: I60af8f9add731bde238fb71f1194e2ea1abd214b
11 files changed