Fixed Show Grid Animation from recent update.

Author: kevzlou7979

gwt-material/src/main/java/gwt/material/design/client/ui/animate/MaterialAnimation.java

@@ -131,7 +131,7 @@ public void run() {
                     break;
                 case SHOW_GRID:
                     widget.addStyleName(CssName.DISPLAY_ANIMATION);
-                    JsMaterialElement.closeGrid(element);
+                    JsMaterialElement.showGrid(element);
                     break;
                 case CLOSE_GRID:
                     widget.addStyleName(CssName.DISPLAY_ANIMATION);