Android shared preferences not saving

From the documentation:

Create a new Editor for these preferences, through which you can make
modifications to the data in the preferences and atomically commit
those changes back to the SharedPreferences object.

Since that’s a new Editor instance, your code should be more like this:

preferences = getApplicationContext().getSharedPreferences(PREFERENCES_NAME, 0);
SharedPreferences.Editor editor = preferences.edit();
editor.putString(SETTINGS_BACKGROUND_IMAGE, "okok");
editor.apply();