SF: Convert to Android.bp

Eliminate the makefiles and convert to using blueprint files for
SurfaceFlinger. Along the way, set up a few things (filegroups,
cc_defaults) to add a unit test build in a change to come.

One configuration feature was dropped, as I was unsure of how to
replicate it in the blueprint configuration:
TARGET_32_BIT_SURFACEFLINGER

Test: Builds, usable on Pixel XL
Test: "atest SurfaceFlinger_test" works (but has failing tests)
Bug: None
Change-Id: I2d574855e53932fbb021afc9d61c4a3bb317330c