[Bug]: Firefox send flow - amount not visible when sending with decimals if the symbol `,` is used instead of `.`

**Describe the bug**

When sending an amount with decimals on Firefox, if the symbol `, `is used instead of` .`, then the amount is not visible.

Unable to reproduce on Chrome.

**Expected behavior**

Sending amount to be visible when it's typed with` ,` same as for Chrome.

**Screenshots/Recordings**

https://github.com/user-attachments/assets/a8126c84-2e1b-4878-9769-8c3fc5d3b7a5

**Steps to reproduce**

1. Go to send flow
2. Type decimal sending amount with the symbol , instead of .
3. Notice it's not fully visible

**Error messages or log output**

```shell

```

**Detection stage**

During release testing

**Version**

13.4.0

**Build type**

None

**Browser**

Firefox

**Operating system**

MacOS

Start by reproducing the issue in the Firefox send flow using MetaMask version 13.4.0, then compare the same decimal input in Chrome. The fix is complete when amounts typed with a comma decimal separator remain fully visible in Firefox as they are in Chrome.

Written by the indexing model from the issue text.