update icon style

dashboard-ui/css/polymer/paper-icon-button-light.css

@@ -3,10 +3,13 @@
     height: 40px;
     padding: 8px;
 }
+    [is=paper-icon-button-light] iron-icon {
+        width: 100%;
+        height: 100%;
+    }
 
-    [is=paper-icon-button-light] iron-icon, [is=paper-icon-button-light] img {
-        /* Don't specify both dimensions or it may not get sized properly */
-        /*width: 100%;*/
+    [is=paper-icon-button-light] img {
+        width: 100%;
         height: 100%;
     }
 
@@ -18,3 +21,9 @@
         background-color: currentcolor !important;
         opacity: .2 !important;
     }
+
+    /* Make sure the img is on top of the ripple */
+    [is=paper-icon-button-light] img {
+        position: relative;
+        z-index: 1;
+    }