Allow creating the "block internal | User Community Feedback

Allow creating the "block internal communication policy" with users exists on multiple groups.

According to the article:

https://help.webex.com/en-us/article/ne9iydeb/Block-Internal-Communication-in-Webex-App-Spaces-for-Your-Organization

Creating the policy is blocked by the system if there's any user exists on the effect of creating this policy with users existing in multiple groups, etc... instead of blocking creating the policy at all, as for some customers the users exist in multiple groups is required to do their daily operations and it's not an option for them to fix the users.