Can not work for AccountId20 network

[AurevoirXavier]

Issue Description

Our session module's key should be AccountId. But it injects some AccountId32 into it.

Auto generated:

"session": {
  "keys": [
    [
      "5DtWrR3CkMhwy5QEnmHqqMKBqSC7fcfnvT8jUykwFoh2seic",
      "5DtWrR3CkMhwy5QEnmHqqMKBqSC7fcfnvT8jUykwFoh2seic",
      {
        "grandpa": "5DaSuaLL4oLxWGR4c1GsvNgSaUuJWw5Pg7DRna5nU2TuNQhp",
        "babe": "5DtWrR3CkMhwy5QEnmHqqMKBqSC7fcfnvT8jUykwFoh2seic",
        "im_online": "5DtWrR3CkMhwy5QEnmHqqMKBqSC7fcfnvT8jUykwFoh2seic",
        "parachain_validator": "5DtWrR3CkMhwy5QEnmHqqMKBqSC7fcfnvT8jUykwFoh2seic",
        "authority_discovery": "5DtWrR3CkMhwy5QEnmHqqMKBqSC7fcfnvT8jUykwFoh2seic",
        "para_validator": "5DtWrR3CkMhwy5QEnmHqqMKBqSC7fcfnvT8jUykwFoh2seic",
        "para_assignment": "5DtWrR3CkMhwy5QEnmHqqMKBqSC7fcfnvT8jUykwFoh2seic",
        "beefy": "KW4wR5T7oX9fZgPyLsMaNyeLZ4HaC8b1iZtuDwQXNjEHYye1x",
        "aura": "5DtWrR3CkMhwy5QEnmHqqMKBqSC7fcfnvT8jUykwFoh2seic",
        "nimbus": "5DtWrR3CkMhwy5QEnmHqqMKBqSC7fcfnvT8jUykwFoh2seic",
        "vrf": "5DtWrR3CkMhwy5QEnmHqqMKBqSC7fcfnvT8jUykwFoh2seic",
        "mixnet": "5DtWrR3CkMhwy5QEnmHqqMKBqSC7fcfnvT8jUykwFoh2seic",
        "bcsv": "5DtWrR3CkMhwy5QEnmHqqMKBqSC7fcfnvT8jUykwFoh2seic",
        "ftsv": "5DaSuaLL4oLxWGR4c1GsvNgSaUuJWw5Pg7DRna5nU2TuNQhp"
      }
    ]
  ]
}

Expected:

"session": {
  "keys": [
    [
      "0x0eef9fabb6eb6fed2ab24a842931f8950426070a",
      "0x0eef9fabb6eb6fed2ab24a842931f8950426070a",
      {
        "aura": "5HTq3xdxVEG3CL68QYaUN72LJakLyRLDiGJXJEAJVxQ7m89c"
      }
    ],
    [
      "0xa858cde8f6cf178786578a3b0becf5c27d18300c",
      "0xa858cde8f6cf178786578a3b0becf5c27d18300c",
      {
        "aura": "5CyMRgKPspo6y357ErtbTz8ZbBkqQ26MXYxCMKZdHeXAWES3"
      }
    ],
    [
      "0x986b41d07776aa48f6d7a80caad49485f9a71714",
      "0x986b41d07776aa48f6d7a80caad49485f9a71714",
      {
        "aura": "5HBWTiQEtz86oPDwWjhTkxWjNDxW8RjZ1WPhWboK8rUWskJm"
      }
    ]
  ]
}

Steps to reproduce the issue

gh repo clone darwinia-network/darwinia
cd darwinia
zombienet-macos-arm64 spawn .maintain/zombienet.toml

Describe the results you received

Error:      Error: Command failed with exit code 1: bash -c tmp/darwinia build-spec --chain /var/folders/8h/_dnjtg3j5jz6bgp1bl5bqzbw0000gn/T/zombie-af881b4658db7afbdef7f5725f328918_-54307-wK8Xq5dmN0G7/koi-genesis-2105-rococo-local-plain.json --disable-default-bootnode  --raw > /var/folders/8h/_dnjtg3j5jz6bgp1bl5bqzbw0000gn/T/zombie-af881b4658db7afbdef7f5725f328918_-54307-wK8Xq5dmN0G7/koi-genesis-2105-rococo-local-raw.json
2024-06-26 17:23:47 Building chain spec    
Error: Service(Other("Invalid JSON blob: invalid length 48, expected a (both 0x-prefixed or not) hex string or byte array containing 20 bytes at line 1 column 3955"))

Describe the results you expected

Run

Zombienet version

Any

Provider

Native

Provider version

## For binaries
Any

Upstream Latest Release

Yes

Additional environment details

No response

Additional information

No response

Screenshots

No response

[AurevoirXavier]

Is possible to not overwrite this file, and I can insert the keys manually through RPC.