[installer, ws-manager]: Use installation shortname in URL templates

[andrew-farries]

Description

As described in #9875, failing image builds currently fail to produce any useful output. A possible cause, as described in this comment, is that the format of the ws-manager WorkspaceURLTemplate strings is wrong.

When we deployed with the old helm chart, these values were set in the relevant configmap like this:

gitpod/chart/templates/ws-manager-configmap.yaml

Lines 74 to 75 in 2f988c9

	"urlTemplate": "https://{{"{{ .Prefix }}"}}.ws{{- if $.Values.installation.shortname -}}-{{ $.Values.installation.shortname }}{{- end -}}.{{ $.Values.hostname }}",
	"portUrlTemplate": "https://{{"{{ .WorkspacePort }}"}}-{{"{{ .Prefix }}"}}.ws{{- if $.Values.installation.shortname -}}-{{ $.Values.installation.shortname }}{{- end -}}.{{ $.Values.hostname }}",

ie, they included a suffix after the ws.

This PR tailors the installer output to produce these URLs in the same way the old helm chart did. Installation short name suffixes like eu-02 are set here:

https://github.com/gitpod-io/ops/blob/main/deploy/production/meta-eu02/app/installer-config.yaml#L6

so the URLs will now look like https://{{ .Prefix }}.ws-eu02.example.com.

Related Issue(s)

Fixes #9875

How to test

I've tested this change in staging by editing the ws-manager configmap in staging to contain the correct URLs, restarting ws-manager and running an image build. I was able to see image build logs as expected:

Release Notes

[installer] Use installation shortname when constructing ws-manager URL templates

Documentation

None

[sagor999]

@andrew-farries I think this change broke preview env.
https://gitpod.slack.com/archives/C032A46PWR0/p1652996871215559