docs(lambda-event-source): improve docstring in KinesisEventSourcePro…

…ps (#29582)

### Issue # (if applicable)

Closes #27321

### Reason for this change

Our customer found `maxRecordAge`  can't be set to `-1` Due to limitation of `cdk.Duration`. However, it's not obvious in the docstring that the [default value](https://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/aws-resource-lambda-eventsourcemapping.html#cfn-lambda-eventsourcemapping-maximumrecordageinseconds) of `maxRecordAge` is already -1. Our customer can simply leave this prop empty to set it to -1. 

So, This PR improves the docstring to make default value more apparent.

See more discussion in the ticket.

### Description of changes

Improve docstring of `maxRecordAge` and `retryAttempts` in `KinesisEventSourceProps` in `aws-lambda-event-source`

### Description of how you validated changes



### Checklist
- [x] My code adheres to the [CONTRIBUTING GUIDE](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md) and [DESIGN GUIDELINES](https://github.com/aws/aws-cdk/blob/main/docs/DESIGN_GUIDELINES.md)

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*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

packages/aws-cdk-lib/aws-lambda-event-sources/lib/stream.ts

@@ -63,7 +63,11 @@ export interface StreamEventSourceProps extends BaseStreamEventSourceProps {
    * * Minimum value of 60 seconds
    * * Maximum value of 7 days
    *
-   * @default - the retention period configured on the stream
+   * The default value is -1, which sets the maximum age to infinite.
+   * When the value is set to infinite, Lambda never discards old records.
+   * Record are valid until it expires in the event source.
+   *
+   * @default -1
    */
   readonly maxRecordAge?: Duration;
 
@@ -73,7 +77,11 @@ export interface StreamEventSourceProps extends BaseStreamEventSourceProps {
    * * Minimum value of 0
    * * Maximum value of 10000
    *
-   * @default - retry until the record expires
+   * The default value is -1, which sets the maximum number of retries to infinite.
+   * When MaximumRetryAttempts is infinite, Lambda retries failed records until
+   * the record expires in the event source.
+   *
+   * @default -1
    */
   readonly retryAttempts?: number;