Include secret manager tip in service accounts list

What does this MR do and why?

Project :: Infra :: Google Cloud contains a component that lists out service accounts for the user.

Let's include a tip that encourages users to learn more about storing and maintaining secrets with a dedicated secret manager.

This commit also refactors strings and introduces a component level i18n object.

No changelog required as everything is behind a feature flag.

Screenshots or screen recordings

🔼 The alert containing the TIP is new.

How to set up and validate locally

1. Use a proper TLD

• This feature integrates with Google OAuth2
• Callback URLs need to be registered via the GCP console
• Google will not accept gdk.test, you will need a proper TLD
  • I use local-gitlab.com
• Setup your GDK for such a domain, update your /etc/hosts and possibly Nginx if used to proxy the GDK port

2. Setup Google Cloud

• Follow the instructions here: https://docs.gitlab.com/ee/integration/google.html
• For the GCP project that is used for OAuth2
  • Enable cloudresourcemanager API
  • Enable iam API

3. Configure GDK for Google OAuth2

• Update gdk.yml and add the Google OAuth2 config

  ---
  hostname: local-gitlab.com
  omniauth:
    google_oauth2:
      client_id: {google_oauth_client_id}
      client_secret: {google_oauth_client_secret}

or, use the CLI to do the same

$ gdk config set omniauth.google_oauth2.client_id '..'
$ gdk config set omniauth.google_oauth2.client_secret '..'

• or, another option is to update the gdk/gitlab/config/gitlab.yml with google_oauth details
• then run: gdk reconfigure

4. Enable Feature Flag

Enable feature flag incubation_5mp_google_cloud

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.