find Common Public Key
fun findCommonPublicKey(arr1: List<PasskeyPublicKey>, arr2: List<PasskeyPublicKey>): PasskeyPublicKey
Finds the unique public key that exists in both arrays, throws error if the common pubkey does not equal to one.
Return
The only common pubkey in both arrays.
Parameters
arr1
The first pubkeys array.
arr2
The second pubkeys array.