[Bug] QR signTransaction throwing an invalid json format error

[vivek-consensys]

Build: 12.15.0
Chrome

1. Install MM
2. Recover from SRP
3. Add hardware wallet (Keystone)
4. Import 3x Keystone accounts
5. Launch Test dApp and connect using Keystone account
6. Deploy ERC721 - (out of memory error displayed on device)
7. Send EIP 1559 txn - (invalid error)

Expected: Both txns to be successful

[dawnseeker8]

The main cause of this issue is still the upgrade of [ethereumjs] upgrade, which change the parameter type to buffer, and to fix this need to upgrade the @keystonehq/metamask-airgrapped-keyring library to use same version we upgraded to, however, the latest version of @keystonehq/metamask-airgapped-keyring 0.15.0 have bug in the code to which rely on @keystonehq/base-eth-keyring in workspace in their package.json file, we may need to fork metamask-airgapped-keyring under metamask to solve this problem.