recovery mode - How do I bypass the RSA authentication dialog box to enable controlling phone from adb?

My phone is Samsung Galaxy S4 SHV-E330S with a broken screen (cannot see or touch anything)

For more context please see my old questions here and here.

I have already tried these:

Can I enable USB debugging using adb?

https://stackoverflow.com/questions/26213954/how-to-solve-adb-device-unauthorized-in-android-adb-host-device

Nothing seems to work. I have pushed the adbkey.pub file in .android folder in the PC to /data/misc/adb/adb_keys in the phone while in recovery. On rebooting to android it was still unauthorized. I am pretty sure that before the screen c\broke AI had developer mode and USB debugging enabled on this phone. regardless, I executed the commands shown here

adb shell mount /system
abd shell

echo "persist.service.adb.enable=1" >> default.prop 
echo "persist.service.debuggable=1" >> default.prop
echo "persist.sys.usb.config=mtp,adb" >> default.prop

echo "persist.service.adb.enable=1" >> /system/build.prop 
echo "persist.service.debuggable=1" >> /system/build.prop
echo "persist.sys.usb.config=mtp,adb" >> /system/build.prop  

since I found out that the above lines of text were not in the original default.prop and /system/build.prop (even though I am pretty sure I had enabled USB debugging before the screen broke). Even after adding these lines, the phone is still unauthorized when I reboot to android. Since then I have recovered the original default.prop and /system/build.prop into the phone.

What else can I try now to bypass the RSA authentication dialog box? I have another rooted android phone (different model and OS version) which I have full access to through adb, but it does not even have an adb_keys folder inside /data/misc/adb/adb_keys, so I can't just copy over from that phone to this phone either.

What else can I do to bypass the RSA authentication dialog box on this phone?