New permission of a parent is propagated to a child element not inheriting permissions

[alansemenov]

1. Choose a content item that has a parent and turn off "Inherit permissions"
2. Open Edit permissions dialog of the parent element from the Details panel
3. Add a new permission (select a role or a user from the dropdown)
4. Click Apply
5. The child element also gets the new permission even though it's not supposed to inherit permissions from the parent

[vbradnitski]

Issue moved to enonic/xp #5887 via ZenHub