Adds eks-pod-identity-agent chart

[joshuabaird]

Issue

N/A -- but related issue here.

Description of changes

This PR adds a Helm chart for the eks-pod-identity-agent.

The eks-pod-identity-agent repo currently contains a Helm chart that is not published to any repository. This PR simply copies that Helm chart into this repo so that we get CI which publishes the chart to aws.github.io/charts.

I opened an issue in the eks-charts repo here.

Checklist

• Added/modified documentation as required (such as the README.md for modified charts)
• Incremented the chart version in Chart.yaml for the modified chart(s)
• Manually tested. Describe what testing was done in the testing section below
• Make sure the title of the PR is a good description that can go into the release notes

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[joshuabaird]

@bwagner5 I'm honestly not sure what the procedure for adding new charts is here. As noted, this chart is currently published over at the eks-pod-identity-agent repo but that repo lacks any CI for publishing the chart to a Helm repository.

[bryantbiggs]

thank you for the PR - however, this should be published directly from the upstream repo to public ECR since that is where it is maintained

ref #1070