Prevent user from changing locked group leader

[HunterACole]

As an operational improvement, please remove the ability to change leaders in an existing group. We want users to have to remove the group and recreate the group to assign the leader of their choice

[code-warriors-llc]

@HunterACole Done changes are on the Testconsle. Please provide feedback after testing and close the issue if implementation meets with requirement Thanks,

[HunterACole]

Looks good on test console