Fix Pipelines UI S3 artifact access

[soleares]

Issue

Artifacts are not viewable from the pipelines UI:

• They don't show their value below the S3 link
• When you click on the link it throws an S3 access denied error

Fix

• Add missing env vars to the ml-pipeline-ui-artifact deployment in each profile namespace. The original PR for this feature mentions that this is necessary: https://github.com/kubeflow/pipelines/pull/1278#issuecomment-591690851
• Update the S3 policy to add GetBucket* permissions. The policy is also tighter and scoped at the bucket resource level and doesn't need permissions at the * resource level.

Testing

Tested on an EKS cluster running latest argoflow-aws distribution with this change and it resolved the above issues.

[soleares]

/CC @DavidSpek

[CodeBooster97]

Thanks worked for me!

[soleares]

Merging this since it's been tested on a few installs. It will also be good to have a working KF 1.3 / KFP 1.6.0 version of S3 artifacts merged because this will need to be updated again as part of upgrading to KF 1.4 / KFP 1.7.1.