Migrate IRegionSamplingListener interface to AIDL

This addresses security vulnerabilities due to hard coded binder
interface.

Bug: 195660647
Test: (1) atest RegionSamplingTest
      (2) install Google I/O 2019 app, tap Agenda menu, scrolling to
      examine the bottom horizontal bar color changes
Change-Id: If2d33c5168b2df5fc7fd8f55e3bca75d3f385a89
diff --git a/services/surfaceflinger/SurfaceFlinger.h b/services/surfaceflinger/SurfaceFlinger.h
index 7339b3b..1545c00 100644
--- a/services/surfaceflinger/SurfaceFlinger.h
+++ b/services/surfaceflinger/SurfaceFlinger.h
@@ -105,6 +105,7 @@
 class FrameTracer;
 class WindowInfosListenerInvoker;
 
+using gui::IRegionSamplingListener;
 using gui::ScreenCaptureResults;
 
 namespace frametimeline {