Fix gl3stub.h

Only define the following before android-L (where new headers define
them already)

  typedef khronos_int64_t  GLint64;
  typedef khronos_uint64_t GLuint64;
  typedef struct __GLsync *GLsync;

Also define L to 9999 for crtbrand.c which needs it to be an integer

Change-Id: I9ed957d70b85cd1cdfeacf11f77203b39c93023d

ndk/sources/android/ndk_helper/gl3stub.h

@@ -14,6 +14,7 @@
  */
 
 #include <GLES2/gl2.h>
+#include <android/api-level.h>
 
 #ifdef __cplusplus
 extern "C"
@@ -64,9 +65,11 @@ GLboolean gl3stubInit();
 /* OpenGL ES 3.0 */
 
 typedef unsigned short GLhalf;
+#if __ANDROID_API__ <= 19
 typedef khronos_int64_t GLint64;
 typedef khronos_uint64_t GLuint64;
 typedef struct __GLsync *GLsync;
+#endif
 
 /*-------------------------------------------------------------------------
  * Token definitions