[WFLY-490][WFLY-2029] If an attribute has access-type=read-only/metric, ...

...make access-control list it with write=false

Previously https://gist.github.com/kabir/6511717#file-gistfile1-json-L29 would be 'true', but since it is read-only, it makes more sense to have write=false in the access-control section.