[bitnami/grafana-tempo] Add persistence options for Grafana Tempo metrics generator

[NeonSludge]

Description of the change

This PR converts the Grafana Tempo metrics generator Deployment into a StatefulSet and adds configurable persistence parameters.

Benefits

The Grafana Tempo metrics generator can now optionally write its WAL to persistent storage. This is important when using the local-blocks processor to enable metrics queries on historical data. This processor requires the traces WAL to be activated (the traces_storage.path option). When this WAL is stored on an emptyDir volume a metrics generator deployment restart will lead to some data loss since the WAL files wil not be available for replay after the restart.

Possible drawbacks

Applicable issues

Additional information

The official tempo-distributed Helm chart allows to deploy the metrics generator as a StatefulSet with persistent volumes (this is disabled by default).This PR also disables the persistence by default to match this behavior.

Checklist

• Chart version bumped in Chart.yaml according to semver. This is not necessary when the changes only affect README.md files.
• Variables are documented in the values.yaml and added to the README.md using readme-generator-for-helm
• Title of the pull request follows this pattern [bitnami/<name_of_the_chart>] Descriptive title
• All commits signed off and in agreement of Developer Certificate of Origin (DCO)