When creating a group there's a checkbox that says "Is this a POSIX group?" which is unchecked by default. Regardless it is checked or not, the group is always created as a posix group.

This is because the UI incorrectly uses "posix" attribute name where as the group-add command takes "nonposix" attribute.

By default CLI will create a posix group unless we specify the --nonposix option. To be consistent, in the UI the label for the checkbox should be changed to "Non-POSIX group" and remain unchecked by default.