Recently Google changed some conditions for publishing apps in the Play Store which make it necessary to leave:
This means that background processing is hard to acomplish. Both apps implement a Bluetooth profile which should be ready at all times, so it must run in the backgrounnd. With API 26 this is only possible by showing a notification icon (currently optional for rSAP). And you still have to manually except the app from power save functions. If your app tries to automatically remove itself from this list it is immediately banned from Play Store.
This affects the phone book app. It's pretty useless without the possibility to transfer call lists to the car. Of course I tried to get an exception for the phone book app by filling out some "Permissions Declaration Form", but I got as answer:
The declared feature (Connected device companion apps) is allowed; however we determined it to be unnecessary for the core functionality of your app.
I don't understand how Google determines that call logs are "unnecessary for the core functionality" of the phone book app, maybe it is some Google AI :-( I guess Google simply rejects all requests.
So I decided to move my phone book app to Amazon Appstore. It is basically the free trial version with the possibility to unlock full functionality with in-app payment. If you already bought the phone book app in Google Play Store it is also unlocked. Update: this only works for me as the developer, sadly not for users :(
In a few weeks the paid version will be unpublished by Google and I will publish a trial version which informs the user about the full version being available in Amazon App Store.
As soon as the rSAP app needs an update it will also move to Amazon...