[Bug]: Sign Message - Clicking Back button in the Bitcoin Snap Sign Message confirmation screen does nothing

**Describe the bug**

Clicking Back button in the Bitcoin Snap Sign Message confirmation screen does nothing.
Same as in Extension https://github.com/MetaMask/metamask-extension/issues/43718

**Expected behavior**

Maybe we should remove the back arrow altogether like in Solana, as it serves no purpose? 🤔

**Screenshots/Recordings**

https://github.com/user-attachments/assets/5d0ef6e1-2531-4f3c-9c67-d520bfe2c3dc

**Steps to reproduce**

1. Go to Bitcoin test dapp
2. Connect
3. Trigger Sign message
4. See back arrow
5. Click it --> see nothing happens

**Error messages or log output**

```shell

```

**Where was this bug found?**

Internal release testing

**Version**

8.0.0

**Build number**

5617

**Build type**

None

**Device**

Pixel 6

**Operating system**

Android

Reproduce the issue from the Bitcoin test dapp on Android by following the listed sign-message steps. Trace the Bitcoin Snap Sign Message confirmation screen; no file or test is named in the report. Done means the back control has an intentional, verified behavior, either navigating correctly or being removed if that is the agreed resolution.

Written by the indexing model from the issue text.