fix cpp

Author: reime005

android/cpp-adapter.cpp

@@ -12,5 +12,5 @@ using namespace std;
 extern "C"
 JNIEXPORT jlong JNICALL
 Java_com_mariusreimer_rncppcode_RNCPPCodeModule_multiply(JNIEnv *env, jclass type, jlong a, jlong b) {
-    return a * b;
-}
+    return example::multiply(a, b);
+}