Expose SurfaceControl's native mLayerId property to Java

Expose the layerId so that we can dump it in WindowManager proto traces. This is to allow us to link windows to their respective layer accurately and consistently from the trace data. This enables Flicker as a Service (go/wm-fass) to tag and assocaite animations across the WindowManager trace and SurfaceFlinger trace and allows us to better display and associate errors across both WM and SF hierarchy views in Winscope.

Test: N/A
Bug: 197712697
Change-Id: Ic11f33b8dc3e134d6c19ac68bfe03f801af04d06