Comment 20 for bug 1803950

Some preliminary tests of deploying more units (aodh in this case) to controller nodes show I might have a solid work around.

instead of:

 - rm -rf /var/lib/apt/lists/*
 - apt clean
 - apt update

being in postruncmd:, we now have it under preruncmd:

3 consecutive tests works, attempting a full deploy now.