fix missing headers

Bug: 33241851
Test: cd system/media && mma -j64 -k BOARD_VNDK_VERSION=current
Change-Id: I7c6e4b271b365f50c376af2925d0f8cbe8e58551
diff --git a/audio_utils/Android.bp b/audio_utils/Android.bp
index abec881..36023f5 100644
--- a/audio_utils/Android.bp
+++ b/audio_utils/Android.bp
@@ -28,6 +28,14 @@
         "roundup.c",
     ],
 
+    header_libs: [
+        "libaudio_system_headers",
+    ],
+
+    export_header_lib_headers: [
+        "libaudio_system_headers",
+    ],
+
     shared_libs: [
         "libcutils",
         "liblog",