helm module should support --reuse-values and allow for update values

[ddl-mmercer]

SUMMARY

Helm has the option to reuse the values used in a deployment, without having to reassign everything. This allows for a more iterative approach when changing only certain values, as you replace the ones you want, and keep the rest. The helm module should support this approach as well

ISSUE TYPE

• Feature Idea

COMPONENT NAME

helm

ADDITIONAL INFORMATION

In the case where a user may not have access to all of the original values outside of helm (ie, for ansible to leverage), re-use values allows for the use of what helm already knows

In the example below, we are specifically reusing all of the values that helm already knows/stores, and either updating or setting new values atop them. In the example, lets assume replicas existed as 1; it is now updated to 2. We also added 'version' as a new value to make tracking easier.. It should account for both of these changes

- name: Deploy latest version of Grafana chart inside monitoring namespace with values
  kubernetes.core.helm:
    name: test
    chart_ref: stable/grafana
    release_namespace: monitoring
    reuse_values: yes
    values:
      replicas: 2
      version: 3e8ec0b2dffa40fb97d5342e4af887de95faa8c61a62480dd7f8aa03dffcf533

[haroonb]

I would also welcome this feature, since a very handy feature of helm.