Hook up event handling in NDK MediaDrm API

Change-Id: I48ac1d3ca5405c5909454c7a553917b31b9a50e5
diff --git a/include/ndk/NdkMediaDrm.h b/include/ndk/NdkMediaDrm.h
index 1322a9d..02619d3 100644
--- a/include/ndk/NdkMediaDrm.h
+++ b/include/ndk/NdkMediaDrm.h
@@ -122,7 +122,7 @@
  *
  * listener is the callback that will be invoked on event
  */
-void AMediaDrm_setOnEventListener(AMediaDrm *, AMediaDrmEventListener listener);
+mediadrm_status_t AMediaDrm_setOnEventListener(AMediaDrm *, AMediaDrmEventListener listener);
 
 /**
  * Open a new session with the MediaDrm object.  A session ID is returned.