This patch updates trove configuration tasks to apply custom_config to
trove-taskmanager/conductor.conf.
Currently only trove.conf is custom-configurable, and the file is to be
loaded by trove-api service only. Therefore, we cannot apply
custom_config to trove-taskmanager/conductor services.
Change-Id: I0a64c4f0df32eb87cd91ebd8eafb512575061413
Closes-Bug: #1706883