Install Janus config files from TinyPilot Debian package (#1552)

Resolves #1496

This change replaces the Ansible task responsible for creating the Janus
config files, implementing it in TinyPilot's Debian package instead.

To test this bundle, run:

```bash
curl \
  --silent \
  --show-error \
  --location \
  https://raw.githubusercontent.com/tiny-pilot/tinypilot/master/scripts/install-bundle | \
  sudo bash -s -- \
    https://output.circle-artifacts.com/output/job/5e8d773d-c381-465e-bd67-425ff99f5cd3/artifacts/0/bundler/dist/tinypilot-community-20230804T1445Z-1.9.0-46+dd77b49.tgz
```
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ansible-role-ustreamer/tasks/install_janus.yml

@@ -17,16 +17,3 @@
   apt:
     name: janus
     default_release: "{{ ustreamer_janus_apt_suite }}"
-
-- name: create Janus config files
-  template:
-    src: "{{ item }}.j2"
-    dest: "{{ ustreamer_janus_configs_dir }}/{{ item }}"
-    owner: root
-    group: root
-    mode: "0644"
-  loop:
-    - janus.jcfg
-    - janus.transport.websockets.jcfg
-  notify:
-    - restart Janus

debian-pkg/debian/tinypilot.postinst

@@ -102,4 +102,12 @@ else
   deb-systemd-invoke start nginx
 fi
 
+# Restore the Janus config files.
+cp \
+  /usr/share/tinypilot/janus.jcfg \
+  /etc/janus/janus.jcfg
+cp \
+  /usr/share/tinypilot/janus.transport.websockets.jcfg \
+  /etc/janus/janus.transport.websockets.jcfg
+
 #DEBHELPER#