Revert "Get rid of IGraphicBufferAlloc"

This reverts commit 78491c9f694cb0767996503c629776a8eda950d7.

Change-Id: I78d5c0a30ab80265f697f681387872b6763b2d1e
diff --git a/libs/gui/Android.bp b/libs/gui/Android.bp
index 9d2dcb6..a1b4abc 100644
--- a/libs/gui/Android.bp
+++ b/libs/gui/Android.bp
@@ -70,9 +70,11 @@
         "DisplayEventReceiver.cpp",
         "FrameTimestamps.cpp",
         "GLConsumer.cpp",
+        "GraphicBufferAlloc.cpp",
         "GuiConfig.cpp",
         "IDisplayEventConnection.cpp",
         "IConsumerListener.cpp",
+        "IGraphicBufferAlloc.cpp",
         "IGraphicBufferConsumer.cpp",
         "IGraphicBufferProducer.cpp",
         "IProducerListener.cpp",