lsr-logs-clean: Normalize image names
    
    Normalize RHEL image names to RHEL-X.Y. Since RHEL images are
    produced quite frequently it is sufficient to keep just one
    RHEL <major>.<minor> after the log expires.
    
    Also add contacts to Linux system roles maintainers.
    
    Signed-off-by: Jiri Kucera <jkucera@redhat.com>