Fix regression for AudioTrack::write() 8-bit PCM

Bug: 7526532
Change-Id: I8ddd1f0e9d035b54401788dcc422591281dcd97a
diff --git a/media/libmedia/AudioTrack.cpp b/media/libmedia/AudioTrack.cpp
index 468bd29..26cf877 100644
--- a/media/libmedia/AudioTrack.cpp
+++ b/media/libmedia/AudioTrack.cpp
@@ -1104,8 +1104,8 @@
         } else {
             toWrite = audioBuffer.size;
             memcpy(audioBuffer.i8, src, toWrite);
-            src += toWrite;
         }
+        src += toWrite;
         userSize -= toWrite;
         written += toWrite;