Fix helm chart service name when using custom release name (#20832)

- created new template fleet.servicename
- reference in all locations that contain service name

Resolves #20830.

# Checklist for submitter

If some of the following don't apply, delete the relevant line.

<!-- Note that API documentation changes are now addressed by the
product design team. -->

- [ ] Changes file added for user-visible changes in `changes/`,
`orbit/changes/` or `ee/fleetd-chrome/changes`.
See [Changes
files](https://github.com/fleetdm/fleet/blob/main/docs/Contributing/Committing-Changes.md#changes-files)
for more information.
- [x] Manual QA for all new/changed functionality

charts/fleet/templates/_helpers.tpl

@@ -23,6 +23,11 @@ If release name contains chart name it will be used as a full name.
 {{- end }}
 {{- end }}
 
+{{- define "fleet.servicename" -}}
+{{- $fullName := include "fleet.fullname" . -}}
+{{- printf "%s-service" $fullName }}
+{{- end }}
+
 {{/*
 Create chart name and version as used by the chart label.
 */}}

charts/fleet/templates/ingress.yaml

@@ -1,5 +1,6 @@
 {{- if .Values.ingress.enabled -}}
 {{- $fullName := include "fleet.fullname" . -}}
+{{- $serviceName := include "fleet.servicename" . -}}
 {{- $svcPort := ternary .Values.fleet.listenPort .Values.fleet.servicePort (eq .Values.fleet.servicePort nil) -}}
 {{- if and .Values.ingress.className (not (semverCompare ">=1.18-0" .Capabilities.KubeVersion.GitVersion)) }}
   {{- if not (hasKey .Values.ingress.annotations "kubernetes.io/ingress.class") }}
@@ -49,11 +50,11 @@ spec:
             backend:
               {{- if semverCompare ">=1.19-0" $.Capabilities.KubeVersion.GitVersion }}
               service:
-                name: {{ $fullName }}
+                name: {{ $serviceName }}
                 port:
                   number: {{ $svcPort }}
               {{- else }}
-              serviceName: {{ $fullName }}
+              serviceName: {{ $serviceName }}
               servicePort: {{ $svcPort }}
               {{- end }}
           {{- end }}

charts/fleet/templates/service.yaml

@@ -1,3 +1,4 @@
+{{- $serviceName := include "fleet.servicename" . -}}
 apiVersion: v1
 kind: Service
 metadata:
@@ -6,7 +7,7 @@ metadata:
     chart: fleet
     heritage: {{ .Release.Service }}
     release: {{ .Release.Name }}
-  name: fleet
+  name: {{ $serviceName }}
   namespace: {{ .Release.Namespace }}
 spec:
   {{- if .Values.gke.ingress.useGKEIngress }}