Thanks for your reply. I found a way to change the setting value without root and without having to use adb on a computer after each reboot. You still need to do it manually, but at least you can do it easily using the phone. I'm sharing below how I did in case you may want to add it to the existing methods:
1. Install
Settings Database Editor app.
2. Allow the app to change system setting by running the following adb command on a computer:
Code:
adb shell pm grant by4a.setedit22 android.permission.WRITE_SECURE_SETTINGS
Fortunatelly this is a persistent change, so you only need to run this comman once, the permission granted to the app will be there even after reboots.
Once the above is done, you don't need a computer anymore to enable call recording, you can do it with the app following these simple steps:
1. Open the app, change the top right drop down to "Global Table".
2. Look for op_voice_recording_supported_by_mcc setting and tap on it.
3. Then tap on "EDIT VALUE", change it to 1, and tap on "SAVE CHANGES".
Done!
It's not as good as having the change applied automatically on each boot, but at least you don't need to have a computer at hand to enable call recording.