[Android] On dalvik, don't use android library

On Android, libglass_lens_android.so could be used, but when running on top of Dalvik, libactivity.so should be used

The following patch fixes this:
diff -r 9f5303fb78fb modules/graphics/src/main/native-prism-es2/eglfb/wrapped_egl.c
--- a/modules/graphics/src/main/native-prism-es2/eglfb/wrapped_egl.c Fri Jun 13 12:36:57 2014 +1200
+++ b/modules/graphics/src/main/native-prism-es2/eglfb/wrapped_egl.c Fri Jun 13 11:05:29 2014 +0200
@@ -156,16 +156,23 @@
     }
 
 #ifdef ANDROID_NDK
+#ifdef DALVIK_VM
+#define ANDROID_LIB "libactivity.so"
+#define GET_NATIVE_WINDOW "android_getNativeWindow"
+#else
+#define ANDROID_LIB "libglass_lens_android.so"
+#define GET_NATIVE_WINDOW "ANDROID_getNativeWindow"
+#endif
     //don't cache for Android!
- printf("Using getAndroidNativeWindow() from glass.\n");
- void *libglass_android = dlopen("libglass_lens_android.so", RTLD_LAZY | RTLD_GLOBAL);
+ printf("Using %s\n", ANDROID_LIB);
+ void *libglass_android = dlopen(ANDROID_LIB, RTLD_LAZY | RTLD_GLOBAL);
     if (!libglass_android) {
- fprintf(stderr, "Did not find libglass_lens_android.so %s\n", dlerror());
+ fprintf(stderr, "Did not find %s %s\n", ANDROID_LIB, dlerror());
            return NULL;
     }
- _ANDROID_getNativeWindow = dlsym(libglass_android, "ANDROID_getNativeWindow");
+ _ANDROID_getNativeWindow = dlsym(libglass_android, GET_NATIVE_WINDOW);
     if (!_ANDROID_getNativeWindow) {
- fprintf(stderr, "Did not find symbol \"ANDROID_getNativeWindow\" %s\n", dlerror());
+ fprintf(stderr, "Did not find symbol \"%s\" %s\n", GET_NATIVE_WINDOW, dlerror());
        return NULL;
     }
     return (*_ANDROID_getNativeWindow)();