Add Support for Custom SSO Icon in GitLab Configuration

Problem Description

GitLab allows you to specify a custom icon in the SSO OmniAuth configuration, however the secret-sso.yaml doesn't support this configuration option.

Proposed Solution

Add support for the icon parameter in the GitLab SSO configuration by modifying the template at line 16 in secret-sso.yaml.

Template Changes

Add the following conditional block to the SSO configuration:

{{- if .Values.addons.gitlab.sso.icon }}
"icon": "{{ .Values.addons.gitlab.sso.icon }}",
{{- end }}

Values Configuration

Users would configure this in their values.yaml file:

addons:
  gitlab:
    sso:
      icon: 'data:image/png;base64,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'