No issue: add CODEOWNERS file.
No issue: add CODEOWNERS file.

I created a new APT subteam to manage this because we're totally going
to forget to update this file and maybe less so the codeowners team.

Based on https://help.github.com/articles/about-codeowners/

mozilla-mobile/focus-android,jonalmeida/focus-android,jonalmeida/focus-android,ekager/focus-android,jonalmeida/focus-android,mozilla-mobile/focus-android,ekager/focus-android,ekager/focus-android,mozilla-mobile/focus-android,ekager/focus-android,jonalmeida/focus-android,mozilla-mobile/focus-android,jonalmeida/focus-android,mozilla-mobile/focus-android,jonalmeida/focus-android,ekager/focus-android,mozilla-mobile/focus-android,ekager/focus-android