ONOS-2074, ONOS-2075 - GUI -- App View Control Button state and icon bug fixes.

Change-Id: Icdaf5ca57963c6e4f30618cb6468c980ac3a786d
diff --git a/web/gui/src/main/webapp/app/directives.js b/web/gui/src/main/webapp/app/directives.js
index f04eca2..bac559b 100644
--- a/web/gui/src/main/webapp/app/directives.js
+++ b/web/gui/src/main/webapp/app/directives.js
@@ -72,8 +72,11 @@
                     iconSize: '@'
                 },
                 link: function (scope, element, attrs) {
-                    is.loadEmbeddedIcon(d3.select(element[0]),
-                                        scope.iconId, scope.iconSize);
+                    attrs.$observe('iconId', function () {
+                        var div = d3.select(element[0]);
+                        div.selectAll('*').remove();
+                        is.loadEmbeddedIcon(div, scope.iconId, scope.iconSize);
+                    });
                 }
             };
         }])