ServiceMonitor template produces invalid YAML due to indent vs nindent in azure-resourcemanager-exporter v 26.1.0

[leandrohinz]

Bug description

Enabling prometheus.monitor.enabled: true on the azure-resourcemanager-exporter chart
(tested with chart 1.3.6, appVersion 26.1.0) makes helm template fail with:

error converting YAML to JSON: yaml: line 6: mapping values are not allowed in this context

Root cause

charts/azure-resourcemanager-exporter/templates/prometheus/servicemonitor.yaml line 8:

labels: {{ include "azure-resourcemanager-exporter.labels" . | indent 4 }}

uses indent 4 instead of nindent 4. Every other template in this same chart
(deployment.yaml, networkpolicy.yaml) correctly uses nindent 4 for the same helper.

This line has actually been broken since 1.2.3 too, but it "accidentally" worked because
_helpers.tpl used to define the label block without trimming the trailing whitespace:

{{- define "azure-resourcemanager-exporter.labels" }}     # chart <= 1.2.3

so the include's output began with a newline, which made indent behave like nindent.

Starting in chart 1.3.0, the define was changed to trim trailing whitespace:

{{- define "azure-resourcemanager-exporter.labels" -}}    # chart >= 1.3.0

which removed that leading newline and exposed the pre-existing indent/nindent bug —
so any chart >= 1.3.0 with prometheus.monitor.enabled: true fails to render.

Steps to reproduce

helm repo add webdevops https://webdevops.github.io/helm-charts/
helm repo update
helm template test webdevops/azure-resourcemanager-exporter \
  --version 1.3.6 \
  --set prometheus.monitor.enabled=true

Expected

Valid YAML manifest for the ServiceMonitor.

Suggested fix

-  labels: {{ include "azure-resourcemanager-exporter.labels" . | indent 4 }}
+  labels: {{- include "azure-resourcemanager-exporter.labels" . | nindent 4 }}