TV: Add Import/Export and Filter Selection Options

### Please answer the following questions for yourself before submitting an issue

- [x] Filters were updated before reproducing an issue
- [x] I checked the [knowledge base](https://adguard.com/kb/) and found no answer
- [x] I checked to make sure that this issue has not already been filed

### AdGuard version

AdGuard for Android TV v4.7

### Environment

Since v4.7 (and possibly earlier), AdGuard for Android TV has been missing two critical features that were previously available in versions 4.3 and beyond:

1. **Import/Export Settings** – The ability to back up and restore settings.
2. **Filter Selection** – The ability to manually select which filters to keep active, including ad, privacy, social, language-specific, and other filters.

These options were present in earlier versions and were functionally identical to the mobile version, as confirmed in [[this previous issue](https://github.com/AdguardTeam/AdguardForAndroid/issues/3597)](https://github.com/AdguardTeam/AdguardForAndroid/issues/3597). There doesn’t appear to be any specific reason for their removal, and it’s possible this is a bug causing certain menu items to be hidden.

Could you confirm whether this is an unintended issue or if these features were deliberately removed?

According to your support team, "We have clarified information with our developers. There were no such option to import/export settings on the AdGuard version for Android TV."

However, as is documented (https://github.com/AdguardTeam/AdguardForAndroid/issues/3597), all of these options were present before.