Last year, Google introduced their own phone app called the Google Phone App. This app also had Call Recording facility and it only worked for Pixel Smart Phones and selected Nokia & Xiaomi Smart Phones.
There was a Call Recording Button on the Ongoing Call Screen that could record the call and notify both parties to the call.
Version 59, the latest version of the Google Phone App, will enable us to record incoming calls in the future. This will automatically record every Unknown call received by the phone.
According to the Disclaimer that they have mentioned about this feature, every call recorded will be notified to the other party and in order to use this call recording facility you will have to agree to allow the call to be recorded first. Also, all these recordings are stored in the internal storage of the smart phone. Also we do not need to record Unknown Calls and it will be recorded automatically.
This feature is not yet available and can be expected in the future.