Optional[customOptional[unknownEncryption algorithm and key length for the generated data key.
ID of the symmetric KMS key that the generated data key should be encrypted with.
If true, the method won't return the data key as plaintext.
Default value is false.
Additional authenticated data (AAD context), optional. If specified, this data will be required for decryption with the [SymmetricDecryptRequest]. Should be encoded with base64.