Copy the flight logs from phone 1 to a computer and then from your computer to phone 2.
That's how I do it and it works with Android phones and a Windows computer.
I have not tried copying the "Flightrecord" folder to a phone but I have copied it from a phone to a computer.
When I have copied logs from the computer to a phone I copied the individual logs, either singly or en masse.
Via windows, if both phones are simultaneously connected to the computer, you might be able to copy straight from one phone to the other but I like a backup.
To create, on the new phone, the file system necessary to recieve the logs it maybe necessary to first fly a flight using the new phone.
It might be possible to blue tooth etc. the files across but I find it easier to do the above and it's probably quicker than blue-toothing etc..
Similarily it maybe possible to sync the logs with DJI and and then download them from DJI but I see no point in that and you may lose the DAT files in the process.