Ko: Third Korean l10n work for release-1.20

- Update outdated files in the dev-1.20-ko.3 (1) (#26131)
- Update outdated files in the dev-1.20-ko.3 branch (2) (#26122)

Co-authored-by: seokho-son <shsongist@gmail.com>
Co-authored-by: Jerry Park <jaehwa@gmail.com>

content/ko/examples/service/access/Dockerfile

@@ -1,4 +1,4 @@
 FROM nginx:1.17.3
 
 RUN rm /etc/nginx/conf.d/default.conf
-COPY frontend.conf /etc/nginx/conf.d
+COPY frontend-nginx.conf /etc/nginx/conf.d