Avoid tracking data when user is not opted-in

[puntope]

Changes proposed in this Pull Request:

When the user is not opted into WooCommerce tracking we should avoid tracking the data for the extension. However, right now we are not doing that and we track the data without checking if the user is opted-in. This PR fixes that.

Checks:

• [x] Does your code follow the WordPress coding standards?
• [ ] Have you written new tests for your changes, as applicable?
• [x] Have you successfully run tests with your changes locally?
• [x] Have you checked to ensure there aren't other open Pull Requests for the same update/change?

Screenshots:

Detailed test instructions:

1. Checkout this PR
2. Run wp option update woocommerce_allow_tracking "no" in WP CLI or set woocommerce_allow_tracking option as "no"
3. Run wp wc tracker snapshot --format=yaml in WPCLI
4. See the wc-google-analytics not appearing in the tracking
5. Run wp option update woocommerce_allow_tracking "yes" in WP CLI or set woocommerce_allow_tracking option as "yes"
6. Run wp wc tracker snapshot --format=yaml in WPCLI
7. . See the wc-google-analytics appearing in the tracking

Additional details:

Changelog entry

Fix - Avoid tracking data when user is not opted-in

[puntope]

WC _Tracks is already preventing to send the data when user is not Opted in. So this check is not necessary.