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
diff --git a/libs/ui/FramebufferNativeWindow.cpp b/libs/ui/FramebufferNativeWindow.cpp
index 1fa2c68..52380a0 100644
--- a/libs/ui/FramebufferNativeWindow.cpp
+++ b/libs/ui/FramebufferNativeWindow.cpp
@@ -250,6 +250,8 @@
 {
     switch (operation) {
         case NATIVE_WINDOW_SET_USAGE:
+        case NATIVE_WINDOW_CONNECT:
+        case NATIVE_WINDOW_DISCONNECT:
             break;
         default:
             return NAME_NOT_FOUND;