Not registering a lifecycle delegate instance causes ubuntuappmanager to segfault

[Jim Hodapp]

If I try and call ua_ui_window_new_for_application_with_properties() without having first installed a lifecycle delegate instance, the call fails because ubuntuappmanager segfaults.

Example code to reproduce:

    UAUiDisplay *display;
    int surface_height, surface_width;
    UAUiWindowProperties *wprops;
    UApplicationDescription *desc;
    UApplicationInstance *uainstance;
    UApplicationLifecycleDelegate *delegate;
    UAUiSession *uasession;
    UAUiSessionProperties *sprops;
    UAUiWindow *window;
    EGLNativeWindowType native_window;

    sprops = ua_ui_session_properties_new();
    ua_ui_session_properties_set_type(sprops, U_SYSTEM_SESSION);
    uasession = ua_ui_session_new_with_properties(sprops);
    if (!uasession)
        GST_WARNING ("Failed to start new UA session");

    display = ua_ui_display_new_with_index(0);

    surface_height = ua_ui_display_query_vertical_res(display);
    surface_width = ua_ui_display_query_horizontal_res(display);

    GST_DEBUG ("Display resolution: (%d,%d)\n",
           surface_height,
           surface_width);

    desc = u_application_description_new();
    delegate = u_application_lifecycle_delegate_new();
    u_application_lifecycle_delegate_set_context(delegate, window_data);
    u_application_description_set_application_lifecycle_delegate(desc, delegate);

    uainstance = u_application_instance_new_from_description_with_options(desc, NULL);
    if (!uainstance)
        GST_WARNING ("Failed to start a new UA instance");

    wprops = ua_ui_window_properties_new_for_normal_window();
    ua_ui_window_properties_set_titlen(wprops, "EglSinkWindow", 13);
    // Use the default role for apps
    ua_ui_window_properties_set_role(wprops, 1);
    GST_DEBUG ("Creating new UA window");
    window = ua_ui_window_new_for_application_with_properties(uainstance, wprops);