We previously auto updated nodepool builders but not launchers when new
container images were present. This created confusion over what versions
of nodepool opendev is running. Use the same behavior for both services
now and auto restart them both.
There is a small chance that we can pull in an update that breaks things
so we run serially to avoid the most egregious instances of this
scenario.
Change-Id: Ifc3ca375553527f9a72e4bb1bdb617523a3f269e
a88adc4101