[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