Adding first APK build

android/app/src/main/cpp/questshock_native.c

@@ -0,0 +1,15 @@
+// android.system.Os has no public chdir() (confirmed against the actual
+// API 34 stub jar - Java has no way to change a process's working
+// directory at all). This is the one bit of native code QuestShockActivity
+// needs, compiled into the same "main" library as engine/ (see
+// android/engine-patches/01-android-shared-lib.patch's ANDROID_EXTRA_SOURCES)
+// - engine/ itself is never modified.
+#include <jni.h>
+#include <unistd.h>
+
+JNIEXPORT void JNICALL
+Java_de_ladkau_questshock_QuestShockActivity_nativeChdir(JNIEnv *env, jclass clazz, jstring path) {
+    const char *cpath = (*env)->GetStringUTFChars(env, path, NULL);
+    chdir(cpath);
+    (*env)->ReleaseStringUTFChars(env, path, cpath);
+}