Draft: Supply externalUrl to prometheus so that alertmanager source links are functional

Package Merge Request

Supplies a default value to monitoring.values.prometheus.prometheusSpec.externalUrl so that the "Source" link/button within alertmanager links to a reachable destination rather than an unreachable, internal Kubernetes service.

Package Changes

N/A

Package MR

N/A

For Issue

Closes big-bang/product/packages/monitoring#233 (closed)

Upgrade Notices

N/A

added monitoring statusdoing teamObservability labels

assigned to @w.griffing

Found a different solution that does not require any changes to upstream (other than incrementing package version eventually). Closing this MR and deleting this branch.

closed