CORE-1827 Rabbitmq start/stop changes for CI

This commit is intended to change the rabbitmq start/stop process
to discover the os-collect-config post-configure.d script such that
the same code will work on CE and EE, as well as pass basic CI
tests.

Change-Id: Ib87dc5d3879d1c3807c395fd01c3e57fb8c457c7