core: PermissionsOperationsParameters cleanup

There are several small issues in this class: a typo in the name itself
and the private prefix in the field names.

Change-Id: Ic6b22e16cb448af5ef831f8afae1ffacfedb0ffe
Signed-off-by: Juan Hernandez <juan.hernandez@redhat.com>
Signed-off-by: Yair Zaslavsky <yzaslavs@redhat.com>