OVB failures due to
- ansible_user variable was used instead of ansible_user_id, the first
one being unreliable as is may only be user defined (or undefined).
- lack of become on tasks that needed it
Fixes problem identified by molecule testing
- lack of idempotence on few tasks
- failure when ansible_user variale was not defined
Change-Id: I11adec7104a59bfa29b00c702eb9b7eb6a5c6766
Depends-On: Iade08ee92d7f48e07a625678d2a1c6ac1cd1982b
Partial-Bug: https://tree.taiga.io/project/tripleo-ci-board/task/358
Closes-Bug: #1802825