fix(fabSpeekDial): remove keyboard handlers on scope destroy

Closes #4681.

src/components/fabSpeedDial/fabController.js

@@ -59,6 +59,9 @@
         angular.forEach(eventTypes, function(eventType) {
           $element.off(eventType, parseEvents);
         });
+        // remove any attached keyboard handlers in case element is removed while
+        // speed dial is open
+        disableKeyboard();
       });
     }
 
@@ -323,4 +326,4 @@
       return $element.find('md-fab-actions');
     }
   }
-})();
+})();