fix issues with glance scripts

- glance was using wrong var name for admin_password
- also missing "\" in several places, breaking multi-line crudini
  commands.
- glance was using wrong tenant name
- in the registry container, glance-manage appears to reference
  glance-api.conf

Change-Id: I280d1db3ed576988f2bf29ea665e1922a37f8752