/usr/lib/mysql-testsuite/suite/rpl/my.cnf is in percona-server-test-5.6 5.6.22-rel71.0-0ubuntu4.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 | # Use settings from rpl_1slave_base.cnf
# add setting to connect the slave to the master by default
!include rpl_1slave_base.cnf
!include include/default_client.cnf
[mysqld.2]
|