Rewrite some flow-style YAML

IMO, flow style is meant for transferring data over the wire.  The syntax
here is easier to read and write when u are working within the luxury of a
static file.

I've confirmed that this represents the same data, using the following
python script:
----
import yaml

data = yaml.load(file('config.yaml', 'r'))
print yaml.dump(data, canonical=True)
----

Change-Id: I45cb9e963d1c199357b37055b8d93eb7159166a2