Use User::groupHasPermission

Instead of getting the rights of group '*' and searching for 'read',
there is a method to do a direct lookup for group '*' and right 'read',
makes the code easier to read.

Change-Id: I1d5d6e1f4a94ded2b3f87144e031d0c2aac62020
Merge "Use User::groupHasPermission"