Fix san-sangeles warnings with clang 3.1

about implicit declaration of functions appInit, appDeinit,
appRender, and importGLInit

Change-Id: Iaaaa49dd8de0e82bcb59be0b08cb490647f06dde
diff --git a/ndk/platforms/android-4/samples/san-angeles/jni/app-android.c b/ndk/platforms/android-4/samples/san-angeles/jni/app-android.c
index feb7549..399d896 100644
--- a/ndk/platforms/android-4/samples/san-angeles/jni/app-android.c
+++ b/ndk/platforms/android-4/samples/san-angeles/jni/app-android.c
@@ -22,6 +22,8 @@
 #include <time.h>
 #include <android/log.h>
 #include <stdint.h>
+#include "importgl.h"
+#include "app.h"
 
 int   gAppAlive   = 1;