Terraform Issue in api-lambda-dynamodb-example

```
api-lambda-dynamodb-example % terraform plan -out tfplan
╷
│ Error: "assume_role_policy" contains an invalid JSON policy: leading space characters are not allowed
│
│ with aws_iam_role.iam_for_lambda,
│ on main.tf line 67, in resource "aws_iam_role" "iam_for_lambda":
│ 67: assume_role_policy = <

Start in main.tf at the aws_iam_role.iam_for_lambda resource around line 67 and reproduce the reported failure with terraform plan -out tfplan. Correct the assume_role_policy heredoc formatting so Terraform accepts the JSON policy, then rerun the plan to confirm the error is gone.

Written by the indexing model from the issue text.