A mismatch between the key names in BondConfig's to_config method
and NetworkDev's netdev_info function was causing subiquity to
crash when creating a bond with a valid transmit hash policy and
then later trying to edit it (LP: #2051586).
The correct key name set by the to_config method should be
"transmit-hash-policy" since this later gets passed to netplan
and neither "xmit-hash-policy" nor "xmit_hash_policy" is a valid
key name in pure netplan config.
Chris Peterson