Deleted Android app resources (#1223)

It appears some of the images related to the Android app
are actually maintained in the app's repo rather than here.

A more thorough clean-up of the `addons` folder should probably
be done at some point!

Remove android app page (gathered from external repo) and
replace it with a placeholder.

Signed-off-by: Yannick Schaus <github@schaus.net>

.vuepress/add_placeholders.rb

@@ -3,23 +3,25 @@
 def add_placeholder_pages()
     puts ">>> Adding placeholder pages for preview"
     [
-        "docs/concepts",
         "docs/configuration/iconsets/classic",
         "docs/configuration/ui/habmin",
         "docs/configuration/ui/habot",
         "docs/configuration/ui/basic",
-        "docs/configuration/ui/basic",
         "docs/configuration/ui/classic",
         "docs/ecosystem/alexa",
         "docs/ecosystem/google-assistant",
         "docs/ecosystem/ifttt",
-        "docs/ecosystem/ifttt",
         "docs/ecosystem/mycroft",
-        "addons/integrations/homekit"
-    ].each { |dir|
-        puts " -> #{dir}/"
-        FileUtils.mkdir_p(dir)
-        File.open("#{dir}/readme.md", "w+") { |f|
+        "addons/integrations/homekit",
+        "docs/apps/android.md"
+    ].each { |path|
+        puts " -> #{path}"
+        page = path
+        if (!(path =~ /\.md/)) then
+            FileUtils.mkdir_p(path)
+            page = path + "/readme.md"
+        end
+        File.open(page, "w+") { |f|
             f.puts "# This content is unavailable"
             f.puts ""
             f.puts "This content is migrated from another repository, and is not included in this preview."

.vuepress/docs-sidebar.js

@@ -86,7 +86,7 @@ module.exports = [
       'configuration/rules-ng',
       'configuration/eclipseiotmarket',
       ['configuration/restdocs', 'REST API'],
-      'apps/android',
+      ['apps/android', 'Android App'],
       'apps/ios',
       'apps/windows',
       ['ecosystem/alexa/', 'Amazon Alexa'],

addons/uis/apps/android.md

@@ -1,64 +0,0 @@
----
-layout: documentation
-title: Android App
-source: https://github.com/openhab/openhab-android/blob/master/docs/USAGE.md
----
-
-{% include base.html %}
-
-<!-- Attention authors: Do not edit directly. Please add your changes to the appropriate source repository -->
-
-# Android App
-
-The openHAB Android application is a native client for openHAB, compatible with phones and tablets.
-The app follows the basic principles of the other openHAB UIs, like Basic UI, and presents your predefined openHAB [sitemap(s)](https://www.openhab.org/docs/configuration/sitemaps.html).
-
-<a href="https://play.google.com/store/apps/details?id=org.openhab.habdroid">
-  <img alt="Get it on Google Play" src="images/en_badge_web_generic.png" width="240px">
-</a>
-<a href="https://f-droid.org/app/org.openhab.habdroid">
-  <img alt="Get it on F-Droid" src="images/get-it-on-fdroid.png" width="240px">
-</a>
-
-## Features
-
-* Control your openHAB server and/or [openHAB Cloud instance](https://github.com/openhab/openhab-cloud), e.g., an account with [myopenHAB](http://www.myopenhab.org/)
-* Receive notifications through an openHAB Cloud connection, [read more](https://www.openhab.org/docs/configuration/actions.html#cloud-notification-actions)
-* Change items via NFC tags
-* Send voice commands to openHAB
-* Supports wall mounted tablets
-
-<div class="row">
-  <div class="col s12 m6"><img src="images/main-menu.png" alt="Demo Overview"></div>
-  <div class="col s12 m6"><img src="images/widget-overview.png" alt="Demo Widget Overview"></div>
-</div>
-
-## Getting Started
-
-On first start the app tries to discover your openHAB server. This will only work on local networks and when the server does not enforce either authentication or HTTPS. If it fails, you can click on `Go to settings` and manually enter the server settings.
-
-The URL field(s) might look like one of the following examples:
-
-* IP address: `http://192.168.1.3:8080`
-* Local hostname: `http://openhabianpi:8080` (depending on your network the suffix `.local` needs to be added to the hostname)
-* Remote domain name: `https://myopenhab.org` for an openHAB cloud account with [myopenHAB](http://www.myopenhab.org/)
-
-**Local server settings:**
-Please enter the base URL of your openHAB server, as you would enter it in the browser to reach the openHAB dashboard.
-
-**Remote server settings:**
-If your openHAB instance is reachable via a public address/domain from outside your home network, these settings will be used when the local connection is not successful.
-Make sure to secure this connection against unauthorized access.
-There are a number of strategies available to provide [secure remote access]({{base}}/installation/security.html) to your openHAB server.
-
-## Permanent Deployment
-
-If you want to use openHAB Android on a wall mounted tablet, go to settings and select `Disable display timer` and `Fullscreen`.
-
-## Help and Technical Details
-
-Please refer to the [openhab-android project on GitHub](https://github.com/openhab/openhab-android) for more details.
-
-## Trademark Disclaimer
-
-Google Play and the Google Play logo are trademarks of Google Inc.