Check os-type and os-version for vps

Fixes: 8712
Signed-off-by: Warren Usui <warren.usui@inktank.com>
To clarify, `return None` is the same as `return` which is the same as not returning. I don't recall mentioning otherwise, sorry if that was misunderstood at some point @wusui 

To do an explicit `return False` is good when you need to use the actual boolean and want to prevent getting a `None`.