SF: Separate SurfaceInterceptor into interface and impl

SurfaceInterceptor is now an abstract interface.
impl::SurfaceInterceptor is the normal implementation.

This allows unit tests to replace it with a GMock.

Test: Builds
Bug: 74827900
Change-Id: I4d5bb2649b0c7a8ec1e6c0abf01ab53174d06a19
7 files changed