android: native: Reset old EmuWindow before constructing a new one.

- Enforces that touch is unregistered at the right time, ensuring it works for subsequent runs.

src/android/app/src/main/jni/native.cpp

@@ -97,6 +97,7 @@ static int RunCitra(const std::string& filepath) {
     if (window) {
         system.Shutdown();
         InputManager::Shutdown();
+        window.reset();
     }
 
     {