aaudio: fix callback size for Legacy input

Set the size of the callback buffer based on the device format
instead of the app format.

Bug: 149249791
Test: atest CtsNativeMediaAAudioTestCases
Change-Id: I0dc5724109a802eea15100782c18986a64e6acd2
diff --git a/media/libaaudio/src/legacy/AudioStreamTrack.cpp b/media/libaaudio/src/legacy/AudioStreamTrack.cpp
index 00963d6..d54d043 100644
--- a/media/libaaudio/src/legacy/AudioStreamTrack.cpp
+++ b/media/libaaudio/src/legacy/AudioStreamTrack.cpp
@@ -196,7 +196,10 @@
 
     // We may need to pass the data through a block size adapter to guarantee constant size.
     if (mCallbackBufferSize != AAUDIO_UNSPECIFIED) {
-        int callbackSizeBytes = getBytesPerFrame() * mCallbackBufferSize;
+        // This may need to change if we add format conversion before
+        // the block size adaptation.
+        mBlockAdapterBytesPerFrame = getBytesPerFrame();
+        int callbackSizeBytes = mBlockAdapterBytesPerFrame * mCallbackBufferSize;
         mFixedBlockReader.open(callbackSizeBytes);
         mBlockAdapter = &mFixedBlockReader;
     } else {