This changes all the puppet 3 validate_* functions
to use the validate_legacy function.
The validate_legacy function has been available since
about three years but require Puppet >= 4.4.0 and since
there is Puppet 4.10.12 as latest we should assume people
are running a fairly new Puppet 4 version.
This is the first step to then remove all validate function
calls and use proper types for parameter as described in spec [1].
[1] https://review.openstack.org/#/c/568929/
Depends-On: https://review.openstack.org/#/c/639215/
Change-Id: Idd720f18893bea0ec1d26859e0a6907a5daa8980
7fea7a2145