general: /usr/lib/ keyfile tests
Add move_keyfile_to_usr_lib_dir and no_uuid_in_keyfile_in_usr_lib_dir.
Both tests checks, how NM treats files in /usr/lib/ directory. If
connection is deleted, NM does nto delete keyfile, but creates
*.nmmeta file in /etc/NetworkManager/system-connections/ (symlink to
/dev/null)