Issue 5049 - Allow embedded WebExtensions in gecko packager

templates/install.rdf.tmpl

 <?xml version="1.0"?>
 
 <!-- This Source Code Form is subject to the terms of the Mozilla Public
    - License, v. 2.0. If a copy of the MPL was not distributed with this
    - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
 
 {%- macro meta() -%}
 <em:creator>{{metadata.get('general', 'author')}}</em:creator>
 
 {%- for contributor in contributors -%}
@@ skipping 11 matching lines @@
     <em:description>{{localeMetadata[defaultLocale].description}}</em:description>
     {{ meta() }}
     {%- if metadata.has_option('homepage', 'default') %}
     <em:homepageURL>{{metadata.get('homepage', 'default')}}</em:homepageURL>
     {%- endif %}
     <em:type>2</em:type>
     <em:bootstrap>true</em:bootstrap>
     {%- if not metadata.has_option('general', 'needMultiprocessShims') %}
     <em:multiprocessCompatible>true</em:multiprocessCompatible>
     {%- endif %}
+    {%- if hasWebExtension %}
+    <em:hasEmbeddedWebExtension>true</em:hasEmbeddedWebExtension>
+    {%- endif %}
 
     {%- if metadata.has_option('general', 'updateURL') %}
     <em:updateURL>
       {{- metadata.get('general', 'updateURL') -}}
       {{- '?reqVersion=%REQ_VERSION%&id=%ITEM_ID%&version=%ITEM_VERSION%&maxAppVersion=%ITEM_MAXAPPVERSION%&status=%ITEM_STATUS%&appID=%APP_ID%&appVersion=%APP_VERSION%&appOS=%APP_OS%&appABI=%APP_ABI%&locale=%APP_LOCALE%&currentAppVersion=%CURRENT_APP_VERSION%&updateType=%UPDATE_TYPE%' -}}
     </em:updateURL>
     {%- endif %}
 
     {%- if metadata.has_option('general', 'icon') %}
     <em:iconURL>{{metadata.get('general', 'icon')}}</em:iconURL>
@@ skipping 55 matching lines @@
         <!-- {{appName}} -->
         <em:id>{{KNOWN_APPS[appName]}}</em:id>
         <em:minVersion>{{metadata.get('compat', appName).split('/')[0]}}</em:minVersion>
         <em:maxVersion>{{metadata.get('compat', appName).split('/')[1]}}</em:maxVersion>
       </Description>
     </em:targetApplication>
     {%- endif %}
     {%- endfor %}
   </Description>
 </RDF>