Fix headers to be inclued alone

See b.android.com/64679 for one of header sys/prctl.h

Change-Id: Ie415ebe2086d2f0190d84fba0c57cc7e1e5822ae

ndk/platforms/android-13/include/android/tts.h

@@ -28,6 +28,8 @@
 extern "C" {
 #endif
 
+#include <stdint.h>
+
 #define ANDROID_TTS_ENGINE_PROPERTY_CONFIG "engineConfig"
 #define ANDROID_TTS_ENGINE_PROPERTY_PITCH  "pitch"
 #define ANDROID_TTS_ENGINE_PROPERTY_RATE   "rate"
@@ -90,7 +92,7 @@ extern android_tts_engine_t *android_getTtsEngine();
 /* Including the old version for legacy support (Froyo compatibility).
  * This should return the same thing as android_getTtsEngine.
  */
-extern "C" android_tts_engine_t *getTtsEngine();
+android_tts_engine_t *getTtsEngine();
 
 // A callback type used to notify the framework of new synthetized
 // audio samples, status will be SYNTH_DONE for the last sample of