Reuse the various service passwords as db passwords.

Reuse the various service passwords as db passwords.

We need to stop using "unset" as the password for all databases. Ideally we
would add a "XxxxDSN" parameter (e.g. KeystoneDSN) but this wont work because
we don't know the VirtualIP to pass in.

Until we can come up with a better solution we should at least get rid of
the "unset" passwords.

Change-Id: I31f45912fa9c116ccdee010a2c5d91ea43a25671
Depends-On: I8ffe1eb481f615b0fbe127cd8107f1e70794c839