MDL-67899 message: Add aria-label to the emoji picker button

lang/en/moodle.php

@@ -2051,6 +2051,7 @@ $string['tocontent'] = 'To item "{$a}"';
 $string['today'] = 'Today';
 $string['todaylogs'] = 'Today\'s logs';
 $string['toeveryone'] = 'to everyone';
+$string['toggleemojipicker'] = 'Toggle emoji picker';
 $string['toomanybounces'] = 'That email address has had too many bounces. You <b>must</b> change it to continue.';
 $string['toomanytags'] = 'This search included too many tags; some will have been ignored.';
 $string['toomanytoshow'] = 'There are too many users to show.';

message/templates/message_drawer_view_conversation_footer_content.mustache

@@ -70,6 +70,7 @@
             </div>
             <button
                 class="btn btn-link btn-icon icon-size-3 ml-1"
+                aria-label="{{#str}} toggleemojipicker, core {{/str}}"
                 data-action="toggle-emoji-picker"
             >
                 {{#pix}} e/emoticons, core{{/pix}}