[Build] Fixes to yaml public build (#5948)

[Build] Fixes to yaml public build (#5948)

* [Build] Don't sign on public builds

* [Build] Use vmImages

* [Build] Fix pool specification

* [Build] Revert back to pool name

* [Build] add osx demands

* [Build] Fix indentation

* [Build] Add more demands

* [Build] Try using certs

* [Build] Try use name

* cert password

* [Build] Add endpoint back

* [Build] Add VSTS feed as variable

* [Build] Add signing stuff

* Fix

* [Build] Try simplify Windows build

* [Build] Publish android apps

* [Build] Add signVmImage