libaaudio: implement callback

Use AudioTrack and AudioRecord TRANSFER_CALLBACK.
Add FixedBlockAdapter to provide fixed size callbacks.

Bug: 36489240
Test: CTS test_aaudio.cpp
Change-Id: Id2034dd640f878dd27fee6b43ad80a01c627dfd6
Signed-off-by: Phil Burk <philburk@google.com>
diff --git a/media/libaaudio/src/client/AudioEndpoint.cpp b/media/libaaudio/src/client/AudioEndpoint.cpp
index 47c4774..90c619c 100644
--- a/media/libaaudio/src/client/AudioEndpoint.cpp
+++ b/media/libaaudio/src/client/AudioEndpoint.cpp
@@ -19,7 +19,7 @@
 #include <utils/Log.h>
 
 #include <cassert>
-#include <aaudio/AAudioDefinitions.h>
+#include <aaudio/AAudio.h>
 
 #include "AudioEndpointParcelable.h"
 #include "AudioEndpoint.h"