Browser update settings doesn't support translation

Problem/Motivation

Browser update settings doesn't support translation for the text message override. In my project I had to alter schema config to add translation for this field

Steps to reproduce

Enable config translation module.
Install and enable "Browser update"
Go to the "/admin/config/regional/config-translation" and notice that there is no possibility to translate browser settings.

Proposed resolution

Update schema and change text_override field type to text.
Create bu.config_translation.yml file to support config translation form

Remaining tasks

User interface changes

API changes

Data model changes