Description of problem:
Changed ethtool settings, then modify the other settings of this interface(or even just touch it), the ethtool settings will get back to the default.

Version-Release number of selected component (if applicable):
nmstate-1.1.0-0.7.alpha7.el8.noarch
nispor-1.1.1-1.el8.x86_64
NetworkManager-1.32.2-1.el8.x86_64

How reproducible:
100%

Steps to Reproduce:
In here using veth to reproduce, but the issue also impacts physical NIC:

# set all ethtool.feature to false
nmstatectl apply << EOF -
interfaces:
- name: veth0
  type: veth
  state: up
  ethtool:
    feature:
      highdma: false
      rx-checksum: false
      rx-gro: false
      rx-gro-list: false
      rx-vlan-hw-parse: false
      rx-vlan-stag-hw-parse: false
      tx-checksum-ip-generic: false
      tx-checksum-sctp: false
      tx-generic-segmentation: false
      tx-gre-csum-segmentation: false
      tx-gre-segmentation: false
      tx-ipxip4-segmentation: false
      tx-ipxip6-segmentation: false
      tx-nocache-copy: false
      tx-scatter-gather-fraglist: false
      tx-sctp-segmentation: false
      tx-tcp-ecn-segmentation: false
      tx-tcp-mangleid-segmentation: false
      tx-tcp-segmentation: false
      tx-tcp6-segmentation: false
      tx-udp_tnl-csum-segmentation: false
      tx-udp_tnl-segmentation: false
      tx-vlan-hw-insert: false
      tx-vlan-stag-hw-insert: false
  veth:
    peer: veth0_p
EOF
nmstatectl show veth0 # all ethtool.feature are "false"
nmstatectl apply << EOF -
interfaces:
- name: veth0
  type: veth
  state: up
EOF
nmstatectl show veth0

Actual results:
some ethtool.feature change back to "true"

Expected results:
Preserved ethtool settings

Additional info: