Rename ISurfaceTexture and SurfaceTexture

The C++ class names don't match what the classes do, so rename
ISurfaceTexture to IGraphicBufferProducer, and SurfaceTexture to
GLConsumer.

Bug 7736700

Change-Id: Ia03e468888025b5cae3c0ee1995434515dbea387
diff --git a/include/gui/BufferItemConsumer.h b/include/gui/BufferItemConsumer.h
index cd4df25..0840891 100644
--- a/include/gui/BufferItemConsumer.h
+++ b/include/gui/BufferItemConsumer.h
@@ -82,7 +82,7 @@
     status_t releaseBuffer(const BufferItem &item,
             const sp<Fence>& releaseFence = Fence::NO_FENCE);
 
-    sp<ISurfaceTexture> getProducerInterface() const { return getBufferQueue(); }
+    sp<IGraphicBufferProducer> getProducerInterface() const { return getBufferQueue(); }
 
 };