API Browser not using externalUri configuration

[CarlosLanderas]

Describe the bug A clear and concise description of what the bug is.

Version of Helm and Kubernetes:

Helm Version:

$ helm version
 version.BuildInfo{Version:"v3.5.2", GitCommit:"167aac70832d3a384f65f9745335e9fb40169dc2", GitTreeState:"dirty", GoVersion:"go1.15.7"}```

Kubernetes Version:

```console
$ kubectl version
Client Version: version.Info{Major:"1", Minor:"19", GitVersion:"v1.19.7", GitCommit:"1dd5338295409edcfff11505e7bb246f0d325d15", GitTreeState:"clean", BuildDate:"2021-01-13T13:23:52Z", GoVersion:"go1.15.5", Compiler:"gc", Platform:"windows/amd64"}
Server Version: version.Info{Major:"1", Minor:"19", GitVersion:"v1.19.7", GitCommit:"14f897abdc7b57f0850da68bd5959c9ee14ce2fe", GitTreeState:"clean", BuildDate:"2021-01-22T17:29:38Z", GoVersion:"go1.15.5", Compiler:"gc", Platform:"linux/amd64"}

Which version of the chart: 4.0.2

What happened:

API Browser not using externalUri configuration

What you expected to happen:

If I use externalUri: 20.73.112.187:9000 the api browser should use the url, 20.73.112.187:9000/api/api-browser but is being exposed as http://graylog-0.graylog.graylog.svc.cluster.local:9000/api/api-browser

Or maybe expose other option to configure the api external uri?

How to reproduce it (as minimally and precisely as possible):

Use the following values.yaml

tags:
  install-mongodb : false
  install-elasticsearch: false
graylog: 
  replicas: 1
  externalUri: 20.73.112.187:9000
  mongodb:
    uri: mongodb://graylog:graylogdev2021!@mongodb:27017/graylog
  elasticsearch:
    hosts: http://elasticsearch-master:9200
    version: 7
  input:
    tcp:
      service:
        type: LoadBalancer
        externalTrafficPolicy: Local
        loadBalancerIP:
      ports:
        - name: gelf1
          port: 12222
        - name: gelf2
          port: 12223
    udp:
      service:
        type: ClusterIP
      ports:
        - name: syslog
          port: 5410

  service:
    type: LoadBalancer
  persistence:
    enabled: true
    storageClass: default-retain

Anything else we need to know:

[junkiebev]

The issue is in 4.x, that setting is http_publish_uri = https://graylog.example.com/ <--note the trailing / and the setting rename