update helm configs so appVersion is used as the tag

[vordimous]

Description

The default values.yaml doesn't need to override the desired image version and can be removed. This will enable a 1-1 relationship between the chartVersion and the appVersion that is already being set in the pom:

 <configuration>
          <chartDirectory>src/main/helm</chartDirectory>
          <chartVersion>${project.version}</chartVersion>
          <appVersion>${project.version}</appVersion>
          ...

The repository is the only unique value we need to default based on the deployment.yaml. Users will be able to overwrite these values in their own values.yaml:

 image: "{{ .Values.image.repository }}:{{ .Values.image.tag | default .Chart.AppVersion }}"

Fixes #487