aaudio: Fix getFramesWritten() for callback mode.

Plus other small fixes for CTS and cleanup

Bug: 37910599
Test: test_aaudio.cpp
Change-Id: I65a23daf99e9de857d3ce9fd12e9f11c614e298e
Signed-off-by: Phil Burk <philburk@google.com>
diff --git a/media/libaaudio/src/legacy/AudioStreamTrack.h b/media/libaaudio/src/legacy/AudioStreamTrack.h
index 29f5d15..186a08e 100644
--- a/media/libaaudio/src/legacy/AudioStreamTrack.h
+++ b/media/libaaudio/src/legacy/AudioStreamTrack.h
@@ -68,6 +68,10 @@
     // This is public so it can be called from the C callback function.
     void processCallback(int event, void *info) override;
 
+    int64_t incrementClientFrameCounter(int32_t frames) override {
+        return incrementFramesWritten(frames);
+    }
+
 private:
 
     android::sp<android::AudioTrack> mAudioTrack;