Infra has adopted the approach of indenting lists an extra level
instead of starting their '-' at the same level as the parent element.
Additionally, Infra uses .yaml extensions instead of .yml extensions.
This role predates Infra having enough ansible to have opinions, so
update it to match current practice.
Also, while we're in there, update when clauses that have an 'and' in
them to just use the list form of when, and change 'include:' to
'include_tasks:'.
Change-Id: Icbeaf99c4d103091ee094e2fa219d7e16229b998
92d5d596b9