The add_filter() calls in the get_message() method are using an old class name, Jetpack_JITM. When a JITM that uses one of these filters is displayed, the JITM's CTA does not work properly and the following PHP warning is generated:

PHP Warning: call_user_func_array() expects parameter 1 to be a valid callback, class 'Jetpack_JITM'

Changes proposed in this Pull Request:

• Fix the add_filter() calls by adding the correct namespace and class name.
• Fix various PHPCS comment errors in the get_messages() method.

Is this a new feature or does it add/remove features to an existing part of Jetpack?

This fixes a bug in an existing feature.

Testing instructions:

1. Install and activate Jetpack and WooCommerce. Do not install WooCommerce Services. Enable debug mode and debug logging.
2. Connect Jetpack.
3. On wp-admin, navigate to WooCommerce -> Settings and set the Country / State to United States (any state).
4. Refresh the WooCommerce -> Settings page.
5. Dismiss the JITMs (which are located above the tabs) until you see one with the button text "Install WooCommerce Services". Do not dismiss this JITM.
6. Check debug.log - you should see the PHP warning for call_user_func_array().
7. Apply this patch.
8. Refresh WooCommerce ->Settings. The "Install WooCommerce Services" JITM should still be displayed at the top of the page.
9. Check debug.log. The PHP warning for call_user_func_array() should not be generated.

Proposed changelog entry for your changes:

• TBD