ci: fix AIO deployment to multiple Firebase sites (#39948)
ci: fix AIO deployment to multiple Firebase sites (#39948)

Since #39853, it is possible to deploy to multiple Firebase sites from a
single branch. In order to deploy to a site, we need to associate an
alias (`aio`) with a site. This is done via the `firebase target:apply`
command. However, when the command is called multiple times, it
associates the alias with many sites, which subsequently fails during
deployment ([example failure][1]), since the `firebase deploy` command
does not know what site to deploy to.

This commit fixes the deployment script by ensuring that any previous
association with the `aio` alias is cleared (via the
`firebase target:clear` command) before associating it with a new site.

[1]: https://circleci.com/gh/angular/angular/871020

PR Close #39948

IdeaBlade/angular,alxhub/angular,angular-indonesia/angular,ocombe/angular,brandonroberts/angular,brandonroberts/angular,IdeaBlade/angular,IdeaBlade/angular,blesh/angular,brandonroberts/angular,JiaLiPassion/angular,gkalpak/angular,blesh/angular,shairez/angular,mgechev/angular,ocombe/angular,shairez/angular,angular/angular,JiaLiPassion/angular,ocombe/angular,gkalpak/angular,alxhub/angular,gnomeontherun/angular,manekinekko/angular,manekinekko/angular,manekinekko/angular,JiaLiPassion/angular,brandonroberts/angular,mgechev/angular,alxhub/angular,angular-indonesia/angular,manekinekko/angular,blesh/angular,gkalpak/angular,angular/angular,shairez/angular,angular/angular,IdeaBlade/angular,shairez/angular,brandonroberts/angular,gnomeontherun/angular,alxhub/angular,mgechev/angular,blesh/angular,alxhub/angular,blesh/angular,IdeaBlade/angular,ocombe/angular,mgechev/angular,ocombe/angular,angular-indonesia/angular,mgechev/angular,angular-indonesia/angular,manekinekko/angular,brandonroberts/angular,ocombe/angular,JiaLiPassion/angular,manekinekko/angular,shairez/angular,gkalpak/angular,gnomeontherun/angular,angular/angular,gnomeontherun/angular