If you are installing VMware Vcenter 6 in your network and you want to set this policy to no expiration. In the VMware 5.5 you could have done this 2 ways like the way below or via the https://vcenter:5480.
The default password lifetime is 90 days, but you can change this lifetime to never expire. To do this you need to edit this policy.
Change the maximum lifetime fomr 90 days to 0 days.
After changing the days to 0 click on OK
After this change you will see that the password never expires.