Artifact registry config instructions setup improvements

What does this MR do and why?

Artifact registry config instructions setup improvements

Adds copy to clipboard button

Use code_block_highlighted component to show syntax highlighted text (slack thread(internal))

Note: Changelog entry is not required since the changes are behind a feature flag.

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Before	After

How to set up and validate locally

1. Simulate a SAAS instance in local GDK

2. In rails console enable the experiment

   Feature.enable(:google_cloud_support_feature_flag)

3. Visit Project > Settings > Integrations > Google Cloud IAM and complete the fields with random values.

4. Visit Project > Settings > Integrations > Google Artifact Registry

5. Under Configuration instructions section

   • Confirm that clipboard button works
   • Confirm that code is syntax highlighted.

Related to #451602 (closed)