Gravity Forms 2.8.7.2

- Fixed PHP notices on the Forms > System Status > Updates page when the plugin is installed in a custom directory.
- AF: Fixed an issue on the installed plugins page where the add-on settings page link could disappear when the list is filtered

- Updated the Members and User Role Editor integrations so the Logging and REST API capabilities are located in the Gravity Forms group instead of the GF Add-Ons group.
- AF: Fixed an issue where the Members integration does not list the Results Page capability for add-ons which register a results page configuration e.g. Polls.

- AF: Added `GFPaymentAddOn::is_valid_payment_amount()` which is called during validation when determining if the add-on should process the submission.
- AF: Added the [gform_{$short_slug}_is_valid_payment_amount](https://docs.gravityforms.com/gform_short_slug_is_valid_payment_amount/) filter.
- AF: Added `GFAddOn::get_short_slug()` to return the add-on slug with the gravityforms prefix removed.
- API: Added the [gf_has_filters](https://docs.gravityforms.com/gf_has_filters/) function to check if a callback is registered for the specified filter.
- API: Added the [gf_has_action](https://docs.gravityforms.com/gf_has_action/) function to check if a callback is registered for the specified action.