Eventarc support for creating triggers for direct events from Apigee API hub is generally available (GA)

## Feature Eventarc support for [creating triggers](https://cloud.google.com/eventarc/docs/event-providers-targets#triggers) for [direct events from Apigee API hub](https://cloud.google.com/eventarc/docs/reference/supported-events#apigee-api-hub) is generally available ([GA](https://cloud.google.com/products#product-launch-stages)).