fix: Velero backup_location to allow s3:actions with or without bucket prefix declaration.

[rodrigobersa]

What does this PR do?

Refactor locals and IAM Policy resources to allow s3:actions on Buckets with or without prefix.

The existing configuration creates an IAM Policy to allow s3:actions in the declared S3 ARN with a Bucket Prefix, however if the customer provides the ARN without a Bucket prefix, the Policy will not allow the s3:actions in the bucket objects or folders.

More

• Yes, I have tested the PR using my local account setup (Provide any test evidence report under Additional Notes)
• Yes, I ran pre-commit run -a with this PR

For Moderators

• E2E Test successfully complete before merge?

Additional Notes

Example with Bucket Prefix

tests/complete

  enable_velero = true
  # An S3 Bucket ARN is required. This can be declared with or without a Prefix.
  velero = {
    # S3 Bucket ARN provided by an S3 Module (module.velero_backup_s3_bucket declared below), without prefix.
    #s3_backup_location = module.velero_backup_s3_bucket.s3_bucket_arn
    # S3 Bucket ARN for an already existing Bucket provided with prefix.
    s3_backup_location = "arn:aws:s3:::backup/dev"
  }

# velero backup-location get                           
NAME      PROVIDER   BUCKET/PREFIX   PHASE         LAST VALIDATED                  ACCESS MODE   DEFAULT
default   aws        dev/dev         Unavailable   2023-04-27 11:52:09 -0400 EDT   ReadWrite     

# aws iam get-policy-version --policy-arn arn:aws:iam::978045894046:policy/velero-20230427002355971300000007  --version-id v4 --query "PolicyVersion.Document.Statement[2].Resource"
"arn:aws:s3:::backup/dev"

---

Example with a Bucket provided by an S3 Module module.velero_backup_s3_bucket without Bucket Prefix

tests/complete

  enable_velero = true
  # An S3 Bucket ARN is required. This can be declared with or without a Prefix.
  velero = {
    # S3 Bucket ARN provided by an S3 Module (module.velero_backup_s3_bucket declared below), without prefix.
    s3_backup_location = module.velero_backup_s3_bucket.s3_bucket_arn
    # S3 Bucket ARN for an already existing Bucket provided with prefix.
    #s3_backup_location = "arn:aws:s3:::backup/dev"
  }

# aws s3 ls
2023-04-27 12:08:07 complete-20230427160804638700000001

# velero backup-location get 
NAME      PROVIDER   BUCKET/PREFIX                         PHASE         LAST VALIDATED                  ACCESS MODE   DEFAULT
default   aws        complete-20230427160804638700000001   Unavailable   2023-04-27 12:08:40 -0400 EDT   ReadWrite     

# aws iam get-policy-version --policy-arn arn:aws:iam::978045894046:policy/velero-20230427002355971300000007  --version-id v5 --query "PolicyVersion.Document.Statement[2].Resource"
"arn:aws:s3:::complete-20230427160804638700000001/*"