New confmap provider: AWS SSM ParameterStore

[its-felix]

Is your feature request related to a problem? Please describe.
The collector currently supports resolving config values from files, environment, yaml, http, s3 and secretsmanager (https://github.com/open-telemetry/opentelemetry-lambda/blob/main/collector/internal/collector/collector.go#L76)

In my case, I'm exporting traces, logs and metrics to Grafana Cloud. To connect to Grafana Cloud, the collector needs to be configured with credentials which should ideally be stored in a secure location.

AWS SecretsManager would be an alternative, but at 0.40$ per Secret it quickly becomes quite expensive for its value.

AWS SSM ParameterStore would be a natural addition in the AWS Ecosystem.

Describe the solution you'd like
Adding a confmap provider which can resolve values from AWS SSM ParameterStore.

Describe alternatives you've considered

• Using Secrets Manager (downside: pretty expensive for little/no benefit compared to ParameterStore)
• Using environment variables (downside: no central configuration for multiple Lambdas)
• Using s3 for the configuration file (downside: management becomes tricky, mixing configuration with secrets)

Additional context
ParameterStore Product Page: https://docs.aws.amazon.com/systems-manager/latest/userguide/systems-manager-parameter-store.html

Existing Issue in contrib: open-telemetry/opentelemetry-collector-contrib#36383
Existing PR in contrib: open-telemetry/opentelemetry-collector-contrib#36384

[serkan-ozal]

@its-felix Thanks for the contribution. Once it is approved, merged and released in the upstream opentelemetry-collector-contrib repo, we can start discussing to include SSM confmap provider in the Lambda collector layer. /cc @tylerbenson