Add a debug option to turn the "transformation hint" off

transformation hint is disabled with:

   adb shell service call SurfaceFlinger 1009 i32 1

Change-Id: I9aafe6f280f88ce41569ed69a06dc522b10e3a88
diff --git a/services/surfaceflinger/Layer.h b/services/surfaceflinger/Layer.h
index 5f0be80..d06a35f 100644
--- a/services/surfaceflinger/Layer.h
+++ b/services/surfaceflinger/Layer.h
@@ -89,6 +89,7 @@
     void onFrameQueued();
     virtual sp<ISurface> createSurface();
     uint32_t getEffectiveUsage(uint32_t usage) const;
+    uint32_t getTransformHint() const;
     bool isCropped() const;
     static bool getOpacityForFormat(uint32_t format);