Bug 1578051 - Apply hovering effect on the info button if it gets tab focus. r=nhnt11

By adding a ':-moz-focusring' on the info button.

Differential Revision: https://phabricator.services.mozilla.com/D45313

--HG--
extra : moz-landing-system : lando

browser/themes/shared/controlcenter/panel.inc.css

@@ -307,7 +307,8 @@
   fill-opacity: 1;
 }
 
-#protections-popup-info-button:hover {
+#protections-popup-info-button:hover,
+#protections-popup-info-button:-moz-focusring {
   outline-color: rgba(12, 12, 13, 0.2);
   background-color: rgba(12, 12, 13, 0.2);
 }