implement connect/disconnect in our native_window_t implementations

the framebuffer implementation doesn't do anything special with this
but the surfaceflinger implementation makes sure the surface is not used
by two APIs simultaneously.

Change-Id: Id4ca8ef7093d68846abc2ac814327cc40a64b66b

libs/ui/FramebufferNativeWindow.cpp

@@ -250,6 +250,8 @@ int FramebufferNativeWindow::perform(android_native_window_t* window,
 {
     switch (operation) {
         case NATIVE_WINDOW_SET_USAGE:
+        case NATIVE_WINDOW_CONNECT:
+        case NATIVE_WINDOW_DISCONNECT:
             break;
         default:
             return NAME_NOT_FOUND;