### Godot version

4.0.rc

### System information

Any

### Issue description

If the RESET animation is generated at the same time as the Bezier track is generated, the bezier edit button will not be active.

![image](https://user-images.githubusercontent.com/61938263/218256176-88b1b196-7b6b-4404-84ad-e8694f23bb1b.png)

Also, if you delete a track in the Bezier Editor, or in undo redo, it will not update correctly.

### Steps to reproduce

![image](https://user-images.githubusercontent.com/61938263/218256230-4b0219d5-87e4-453a-8294-59f8feb0cfd5.png)


### Minimal reproduction project

N/A
return play_position_pos;
}
void AnimationTimelineEdit::update_play_position() {
	play_position->queue_redraw();
}
void AnimationTimelineEdit::update_values() {
	if (!animation.is_valid() || editing) {
		return;
	}
	editing = true;
	if (use_fps && animation->get_step() > 0) {
		length->set_value(animation->get_length() / animation->get_step());
		length->set_step(1);
		length->set_tooltip_text(TTR("Animation length (frames)"));
		time_icon->set_tooltip_text(TTR("Animation length (frames)"));
		if (track_edit) {
			track_edit->editor->_update_key_edit();
		}
	} else {
		length->set_value(animation->get_length());
		length->set_step(0.0001);
		length->set_tooltip_text(TTR("Animation length (seconds)"));
		time_icon->set_tooltip_text(TTR("Animation length (seconds)"));
	}
	switch (animation->get_loop_mode()) {
		case Animation::LOOP_NONE: {
			loop->set_icon(get_theme_icon(SNAME("Loop"), SNAME("EditorIcons")));
			loop->set_pressed(false);
		} break;