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/AudioStreamLegacy.h b/media/libaaudio/src/legacy/AudioStreamLegacy.h
index c109ee7..d5a3ede 100644
--- a/media/libaaudio/src/legacy/AudioStreamLegacy.h
+++ b/media/libaaudio/src/legacy/AudioStreamLegacy.h
@@ -70,6 +70,8 @@
     // Implement FixedBlockProcessor
     int32_t onProcessFixedBlock(uint8_t *buffer, int32_t numBytes) override;
 
+    virtual int64_t incrementClientFrameCounter(int32_t frames)  = 0;
+
 protected:
     FixedBlockAdapter         *mBlockAdapter = nullptr;
     aaudio_wrapping_frames_t   mPositionWhenStarting = 0;