Попробуйте, удалите requestParameters из конца.
{
"source": [
"aws.rds"
],
"detail-type": [
"AWS API Call via CloudTrail"
],
"detail": {
"eventSource": [
"rds.amazonaws.com"
],
"eventName": [
"CreateDBInstance"
],
"requestParameters": {
"dBInstanceIdentifier": [
"database"
]
}
}
}