Code refactoring: remove include/private/media/ directory.

Keep the existing code pattern that private .h files are named as
XXXPriv.h and stored in media/ndk/ directory.

Bug: 149835919
Test: AImageReaderWindowHandleTest
Change-Id: Iec99e8ad2c9e4bd7cf96f685d91b47e8fb80c9a8
diff --git a/media/ndk/tests/AImageReaderWindowHandleTest.cpp b/media/ndk/tests/AImageReaderWindowHandleTest.cpp
index 5b65064..27864c2 100644
--- a/media/ndk/tests/AImageReaderWindowHandleTest.cpp
+++ b/media/ndk/tests/AImageReaderWindowHandleTest.cpp
@@ -17,10 +17,10 @@
 #include <gtest/gtest.h>
 #include <media/NdkImageReader.h>
 #include <media/NdkImage.h>
-#include <private/media/NdkImage.h>
 #include <mediautils/AImageReaderUtils.h>
 #include <gui/IGraphicBufferProducer.h>
 #include <gui/bufferqueue/1.0/H2BGraphicBufferProducer.h>
+#include <NdkImagePriv.h>
 #include <NdkImageReaderPriv.h>
 #include <vndk/hardware_buffer.h>
 #include <memory>