feat(flex-linux-setup): installer should pull static admin-ui build from repository url rather than creating build during installation

[duttarnab]

Changes to the steps for installing the Admin UI:

1, Flex installer will not generate admin-ui built from the flex main branch. Please remove all the steps required to built admin-ui from the repository.

It will directly pull and extract admin-ui built from https://jenkins.gluu.org/npm/admin_ui/main/built/admin-ui-main-built.tar.gz to /var/www/html/admin directory (apache2 deploy directory).

2. Create env-config.js in /var/www/html/admin directory with the following contents.

const CONFIG_API_BASE_URL = "https://%(hostname)s/jans-config-api"
const API_BASE_URL = "https://%(hostname)s/jans-config-api/admin-ui"
const BASE_PATH = "/admin/"

window.configApiBaseUrl = CONFIG_API_BASE_URL
window.apiBaseUrl = API_BASE_URL
window.basePath = BASE_PATH

The %(hostname)s should be replace by config-api hostname.