[Other] Car Thing Set Default Service

[Carter5]

The latest update allowed Car thing to be able to control other media services as well as Spotify. However this poses a huge problem to users like myself. Previously I could get into the car and Car thing would start playing Spotify for me instead of the default Apple Music. Now, since it can control Apple Music, I have to manually select Spotify myself. Introduce a setting to select the default service as Spotify to reintroduce the functionality that many Apple users purchased Car Thing for.