Fix issue #3117918: No way to finish a native activity

Change-Id: Ic53e712f7ab5412d72a31b96ecba252344b91644
diff --git a/native/android/native_activity.cpp b/native/android/native_activity.cpp
index 0c6823a..056255f 100644
--- a/native/android/native_activity.cpp
+++ b/native/android/native_activity.cpp
@@ -21,6 +21,10 @@
 
 using namespace android;
 
+void ANativeActivity_finish(ANativeActivity* activity) {
+    android_NativeActivity_finish(activity);
+}
+
 void ANativeActivity_setWindowFormat(ANativeActivity* activity, int32_t format) {
 	android_NativeActivity_setWindowFormat(activity, format);
 }