ipa[server,replica]: Set _packages_adtrust for Ubuntu

freeipa-server-trust-ad has been added to the package list for adtrust for
Ubuntu.

roles/ipareplica/vars/Ubuntu.yml

 # vars/Ubuntu.yml
 ipareplica_packages: [ "freeipa-server" ]
 ipareplica_packages_dns: [ "freeipa-server-dns" ]
-ipareplica_packages_adtrust: [ ]
+ipareplica_packages_adtrust: [ "freeipa-server-trust-ad" ]

roles/ipaserver/vars/Ubuntu.yml

 # vars/Ubuntu.yml
 ipaserver_packages: [ "freeipa-server" ]
 ipaserver_packages_dns: [ "freeipa-server-dns" ]
-ipaserver_packages_adtrust: [ ]
+ipaserver_packages_adtrust: [ "freeipa-server-trust-ad" ]