fix(lambda-promtail): Add asterisk to log group ARN to allow writing to log streams

[gmeligio]

What this PR does / why we need it:
The current ARN format in aws_iam_policy_document.lambda_cloudwatch which is aws_cloudwatch_log_group.this.arn doesn't allow to write logs because it's missing permissions for logs streams. Instead, an * should be appended to fix this permission like in "${aws_cloudwatch_log_group.this.arn}:*"

Which issue(s) this PR fixes:
No issue created.

Special notes for your reviewer:
Tested with

module "lambda_promtail" {
  source = "github.com/gmeligio/loki//tools/lambda-promtail?ref=promtail-loggroup-arn"

  bucket_names          = local.bucket_names
  lambda_promtail_image = "my-image"
  write_address         = var.write_address
  username              = var.username
  password              = var.password
}

Checklist

• Reviewed the CONTRIBUTING.md guide (required)
• Documentation added
• Tests updated
• CHANGELOG.md updated
  • If the change is worth mentioning in the release notes, add add-to-release-notes label
• Changes that require user attention or interaction to upgrade are documented in docs/sources/setup/upgrade/_index.md
• For Helm chart changes bump the Helm chart version in production/helm/loki/Chart.yaml and update production/helm/loki/CHANGELOG.md and production/helm/loki/README.md. Example PR
• If the change is deprecating or removing a configuration option, update the deprecated-config.yaml and deleted-config.yaml files respectively in the tools/deprecated-config-checker directory. Example PR

[CLAassistant]

All committers have signed the CLA.

[gmeligio]

Couldn't find the issue posted before. Found the existing #10908 that will be solved by #10909, with very similar changes to this PR. That PR will be enough, so it's better to close this one.