Revert^2 "hwui: remove FatVector"

Revert submission 10449863-revert-fatvector

Reason for revert: b/149254345

Original change (of introducing FatVector) was reverted as a stop-gap solution to fix the aforementioned bug.

The bug was caused by an ABI lock between Surface's definition (that changed with Region) and lib-imsvt prebuilt.

Enabling this change now as we have re-compiled the prebuilt with the change enabled. Doing that via a revert of the revert.

Reverted Changes:
I8ac66acb8:Revert "hwui: remove FatVector"
Ib60dbf3ef:Revert "libui: rewrite Region with FatVector"

Original changes:
I09dc2fddd:hwui: remove FatVector
I265c6c831:libui: rewrite Region with FatVector

bug: 149254345

Change-Id: I9fb5e8908434abb9a763992e922445a2dc37e865
diff --git a/libs/hwui/RenderNode.h b/libs/hwui/RenderNode.h
index d55e5b0..c0ec217 100644
--- a/libs/hwui/RenderNode.h
+++ b/libs/hwui/RenderNode.h
@@ -27,6 +27,8 @@
 
 #include <androidfw/ResourceTypes.h>
 
+#include <ui/FatVector.h>
+
 #include "AnimatorManager.h"
 #include "CanvasTransform.h"
 #include "Debug.h"
@@ -35,7 +37,6 @@
 #include "RenderProperties.h"
 #include "pipeline/skia/SkiaDisplayList.h"
 #include "pipeline/skia/SkiaLayer.h"
-#include "utils/FatVector.h"
 
 #include <vector>