display alert dialog when switch ota server

Description

Issue(s)

https://gitlab.e.foundation/e/backlog/-/issues/4881

Test procedures

build a pie device with 4881-pie-confirmation-ota feature branch

go to developper option, enable staging OTA server, you should get a dialog asking for confirmation like the one in screenshots

Technical details

Screenshots

Check list

• Self review
• Test procedure explained
• Tested on fresh install
• Tested applied as an update
• License
• Internal documentation
• User documentation