### 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
timeline->update_play_position();
	_redraw_tracks();
	for (int i = 0; i < track_edits.size(); i++) {
		track_edits[i]->update_play_position();
	}
	_redraw_groups();
	bezier_edit->queue_redraw();
	bezier_edit->update_play_position();
}
int AnimationTrackEditor::_get_track_selected() {
	for (int i = 0; i < track_edits.size(); i++) {
		if (track_edits[i]->has_focus()) {
			return i;
		}
	}
	return -1;
}
void AnimationTrackEditor::_insert_key_from_track(float p_ofs, int p_track) {