Prometheus data source uid no longer explicitly set

Bug

Description

We have custom grafana dashboards that are referencing the prometheus datasource via uid prometheus, as previously set here https://repo1.dso.mil/big-bang/product/packages/monitoring/-/blob/45.27.2-bb.4/chart/values.yaml?ref_type=tags#L1057 before grafana was split out into its own separate chart as part of BB 2.7.0.

It appears that no default datasources are specified at the package level anymore (https://repo1.dso.mil/big-bang/product/packages/grafana/-/blob/6.57.4-bb.0/chart/values.yaml?ref_type=tags#L555), and instead this is handled all at the BigBang default values level (chart/templates/grafana/values.yaml) as introduced here: 62e195ce

The uid prometheus is no longer specified, so it appears one is dynamically generated at deploy time. This setup isn't consistent though, as a uid is still explicitly specified for tempo: 62e195ce

Request is to once again explicitly specify the uid of prometheus for the prometheus data source for easy reference in custom dashboards and continuity with existing deployments where the datasource already exists as such.

BigBang Version

2.10.0, though this issue was introduced with BB 2.7.0