DisplayManager: Add an API to query for DISPLAY_DECORATON

Tunnel through SurfaceControl to determine whether the HWC has this
capability. This allows clients (i.e. SystemUI) to know whether they can
use Composition.DISPLAY_DECORATON. If so, they may want to render
differently (i.e. in A8). See Ib948c38ee189877eda675a6342cb70099f66122b
for an example.

Bug: 193170859
Test: manual
Test: TODO
Change-Id: I9904452b6408199bb1f86de9e21132e4d4444e1a