brave-browser: [Desktop] Unable to delete/remove created wallet in Crypto wallets

Description

Some users are unable to delete/remove a created wallet in crypto wallets. Once reaching the appropriate menu, the Save and Cancel options disappear and the user is returned to the main page, the wallet is not actually deleted.

Steps to Reproduce

1. Go brave://wallet/.
2. Click on your profile avatar
3. Click on Settings
4. Click on Contacts
5. Click on My Wallet Accounts
6. Select the wallet you want to view
7. Click Edit
8. Click Delete Account

Actual result:

User is returned to main page, deleted wallet remains.

Expected result:

Wallet/account should be removed.

Reproduces how often:

Easily (for the user)

Brave version (brave://version info)

Windows 10 64 Bit Home. Brave Version - [Version 1.11.101 Chromium: 84.0.4147.89 (Official Build) (64-bit)]:

Version/Channel Information:

• Can you reproduce this issue with the current release? Y
• Can you reproduce this issue with the beta channel? N/A
• Can you reproduce this issue with the nightly channel? N/A

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields? N/A
• Does the issue resolve itself when disabling Brave Rewards? N/A
• Is the issue reproducible on the latest version of Chrome? N/A

Miscellaneous Information:

Original user report: https://community.brave.com/t/i-cant-delete-my-2nd-wallet/146316

@ryanml mentions a likely fix in upcoming version update, when we rebase to MetaMask v8: https://bravesoftware.slack.com/archives/CBP2ZKC0H/p1596040670372800