fix default rabbitmq configuration values in sample cfgs

The rabbit_* configuration options have default values in the library
code, but they are not visible in the sample configuration file. This
change adds the config values to the sample configuration files.

It also removes the other unused notifier_* config attributes.

Change-Id: I4ae76ef78b7a0a04c2ea5a24fd3000e9c1561f81
Closes-Bug: #1281975
Merge "fix default rabbitmq configuration values in sample cfgs"