Update PluginPolygon.java

Removed unnecessary code setting the visibility of the polygon hardcoded to true/false.
This is not needed, since the visibility is managed by the PolygonOptions.

src/android/plugin/google/maps/PluginPolygon.java

@@ -339,11 +339,6 @@ public void setPoints(final JSONArray args, final CallbackContext callbackContex
             public void run() {
                 // Update the polygon
                 polygon.setPoints(path);
-                if (path.size() > 0) {
-                    polygon.setVisible(true);
-                } else {
-                    polygon.setVisible(false);
-                }
                 callbackContext.success();
             }
         });