Fix 'is_live' value in account summary

[Mayisha]

Fixes p1732003649743799-slack-C055WHLA98D

Changes proposed in this Pull Request:

Return 'is_live' as true in the account summary response when test mode is disabled in gateway settings and charge is enabled in the Stripe account.

Testing instructions

Code review should be enough.

[staskus]

Thank you!

✅

Before this change:

• WP-Admin showed both Stripe extension and connected account are in Test Mode
• However GET /?rest_route=/wc/v3/wc_stripe/account/summary&_fields=status%2Cis_live%2Ctest_mode returned is_live: true and test_mode: true for the site.

It prevented mobile app payments from being taken from the app.

After this change:

• WP-Admin shows both Stripe extension and connected account are in Test Mode
• GET /?rest_route=/wc/v3/wc_stripe/account/summary&_fields=status%2Cis_live%2Ctest_mode returns is_live: false and test_mode: true for the site.

Testing mobile app payments works as expected again.

[wjrosa]

Thanks for this fix, Mayisha! Code is good 👍