Optimize BLAST buffer releases via Unix sockets

Bug: 294133380
Flag: com.android.graphics.libgui.flags.buffer_release_channel
Test: BLASTBufferQueueTest
Change-Id: Ia183452198dadc7f8e540f7219bd44d8b5823458
diff --git a/libs/gui/libgui_flags.aconfig b/libs/gui/libgui_flags.aconfig
index 74d806e..e8f2b76 100644
--- a/libs/gui/libgui_flags.aconfig
+++ b/libs/gui/libgui_flags.aconfig
@@ -51,3 +51,11 @@
   bug: "322036393"
   is_fixed_read_only: true
 } # edge_extension_shader
+
+flag {
+  name: "buffer_release_channel"
+  namespace: "window_surfaces"
+  description: "Enable BufferReleaseChannel to optimize buffer releases"
+  bug: "294133380"
+  is_fixed_read_only: true
+} # buffer_release_channel