### 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
emit_signal(SNAME("animation_len_changed"), p_new_len);
}
void AnimationTrackEditor::_dropped_track(int p_from_track, int p_to_track) {
	if (p_from_track == p_to_track || p_from_track == p_to_track - 1) {
		return;
	}
	_clear_selection(true);
	EditorUndoRedoManager *undo_redo = EditorUndoRedoManager::get_singleton();
	undo_redo->create_action(TTR("Rearrange Tracks"));
	undo_redo->add_do_method(animation.ptr(), "track_move_to", p_from_track, p_to_track);
	
	int to_track_real = p_to_track > p_from_track ? p_to_track - 1 : p_to_track;
	undo_redo->add_undo_method(animation.ptr(), "track_move_to", to_track_real, p_to_track > p_from_track ? p_from_track : p_from_track + 1);
	undo_redo->add_do_method(this, "_track_grab_focus", to_track_real);
	undo_redo->add_undo_method(this, "_track_grab_focus", p_from_track);
	undo_redo->commit_action();
}
void AnimationTrackEditor::_new_track_node_selected(NodePath p_path) {