Add policy to allow shill to use Binder

Also, add policies and macros to allow shill to register its Manager
with ServiceManager, and for other services to communicate
with shill over Binder.

TEST: Build shill with Binder by manually setting the
      SHILL_USE_BINDER variable in its Android.mk file,
      and verify from 'adb logcat | grep denied' no avc denials
      are logged for shill.
TEST: shill_setup_wifi works on a Binder-enabled shill build.
BUG: 25160005

Change-Id: I4b80bb1b2b225b7b1accd6e5a714110e87005210
6 files changed