Pass `service_version=v4` to the service when the `setupFlowRefreshPhase4` feature flag is enabled.

[techanvil]

Feature Description

We need to bump the service_version value that is passed to the service to v4 when the setupFlowRefreshPhase4 feature flag is enabled.

This is a dependency for the service task to update the progress indicator for SFR phase 4.

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Acceptance criteria

• The service_version value that is passed to the service is set to v4 when the setupFlowRefreshPhase4 feature flag is enabled.
• This change is made in all cases where the value is passed to the service.

Implementation Brief

• In includes/Core/Authentication/Google_Proxy.php:
  • Update the service_version logic used in get_site_fields() and get_metadata_fields().
  • Set service_version to v4 when setupFlowRefreshPhase4 is enabled.
  • Keep the existing behaviour unchanged when the setupFlowRefreshPhase4 is disabled.
• In includes/Modules/Analytics_4/Datapoints/Create_Account_Ticket.php:
  • Update the redirect URI service_version assignment to use v4 when setupFlowRefreshPhase4 is enabled.

Test Coverage

• Add/adjust PHPUnit assertions for all existing service_version pass-through paths when setupFlowRefreshPhase4 is enabled.
• Verify existing assertions continue to pass when setupFlowRefreshPhase4 is disabled.
• Fix any failing tests.

QA Brief

Changelog entry

[techanvil]

IB ✅

[techanvil]

I've moved this back to AC, as it looks like they will need to be adjusted.

[techanvil]

Hi @eugene-manuilov, @aaemnnosttv suggested on Slack that you could pick this issue up, would that be OK?