media: Do not use forward declaration for AudioPlaybackRate

AudioPlaybackRate becomes a typedef from a C struct,
thus forward declaring it as "struct AudioPlaybackRate"
is not correct anymore.

Bug: 133526565
Test: m
Change-Id: I400049d8445640dc40937ff9e9891ef8c7ad8094
diff --git a/media/jni/android_media_MediaSync.h b/media/jni/android_media_MediaSync.h
index 6f80885..09d69d1 100644
--- a/media/jni/android_media_MediaSync.h
+++ b/media/jni/android_media_MediaSync.h
@@ -17,6 +17,7 @@
 #ifndef _ANDROID_MEDIA_MEDIASYNC_H_
 #define _ANDROID_MEDIA_MEDIASYNC_H_
 
+#include <media/AudioResamplerPublic.h>
 #include <media/stagefright/foundation/ABase.h>
 #include <media/stagefright/MediaSync.h>
 #include <utils/Errors.h>
@@ -24,7 +25,6 @@
 
 namespace android {
 
-struct AudioPlaybackRate;
 class AudioTrack;
 class IGraphicBufferProducer;
 struct MediaClock;