Use product analytics experiment

What does this MR do and why?

Recently, a new toggle 'Product analytics' is added to group settings, which can be only enabled if 'Experiment and Beta features' is also enabled.

This MR adds a check for that toggle value in order to show product analytics dashboards.

Note: No changelog is added as the feature is behind a feature flag.

Screenshots or screen recordings

Experiment/Beta Toggle	Product Analytics Toggle	Expectation	Screenshot
Off	Off	Value Stream Dashboard is visible, product analytics dashboards are not
Off	On	N/A this configuration is not possible.	N/A this configuration is not possible.
On	Off	Value Stream Dashboard is visible, product analytics dashboards are not
On	On	Value Stream Dashboard and product analytics dashboards are visible

How to set up and validate locally

Numbered steps to set up and validate the change are strongly suggested. ow:

1. Visit group settings page -> Permissions and group features
2. Enable "Experiment and Beta features" and "Product Analytics" toggles
3. Visit a project which has product analytics dashboards
4. Click Analyze -> Analytics dashboards
5. You should see product analytics dashboards, value stream dashboard and custom dashboards (if any)
6. Go to group settings page and disable "Product Analytics" toggle
7. Visit the same project which has product analytics dashboards
8. Click Analyze -> Analytics dashboards
9. You should not see product analytics dashboards. You should still see value stream dashboard and custom dashboards (if any)

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.

Related to #414865 (closed)