Add BufferReleaseChannel

BufferReleaseChannel will be used to communicate buffer releases from SurfaceFlinger to BLASTBufferQueue.

Bug: 294133380
Flag: com.android.graphics.libgui.flags.buffer_release_channel
Test: BufferReleaseChannelTest
Change-Id: Ic38e8eefc96abc0b2bbe780115b7628413e8b829
diff --git a/libs/gui/Android.bp b/libs/gui/Android.bp
index 51d2e53..1243b21 100644
--- a/libs/gui/Android.bp
+++ b/libs/gui/Android.bp
@@ -255,6 +255,7 @@
         "BitTube.cpp",
         "BLASTBufferQueue.cpp",
         "BufferItemConsumer.cpp",
+        "BufferReleaseChannel.cpp",
         "Choreographer.cpp",
         "CompositorTiming.cpp",
         "ConsumerBase.cpp",