ApiCallAttemptTimeout tracks the amount of time for a single http attempt and the request can be retried if timed out on api call attempt.
ApiCallTimeout configures the amount of time for the entire execution including all retry attempts.
Checkout this best practices guide for more details - https://github.com/aws/aws-sdk-java-v2/blob/97ee691a1a4f689a238f4a92acc4908f87979f05/docs/BestPractices.md?plain=1#L56