refactor drools chart to allow customizations

refactor drools chart to allow customizations

- move some values out of .conf files to values to avoid
  building the chart when deploying policy (drools).
- move credentials to a single secret file, this is precursor
  work to deal with confidential info in a better way in
  future releases.
- delete unused files.
- generify mounting of configmaps/secrets as volumes to
  avoid explicitly having to modify statefulset.yaml.
- update amsterdam controller with latest version in nexus
  at container instantiation.
- update to the latest released drools image.

Issue-ID: POLICY-1371
Signed-off-by: jhh <jorge.hernandez-herrero@att.com>
Change-Id: I1497b61cd210ac4c00b957c2832de5acd01ea4d2
Signed-off-by: jhh <jorge.hernandez-herrero@att.com>