docs(elasticloadbalancingv2): set proper default for stickiness (#29726)

By default, stickiness is disabled. The duration _is_ one day if stickiness is enabled,
but we don't surface that option to users. If `stickinessCookieDuration` is not 
supplied, stickiness will not be enabled so the 1 day default doesn't make sense here.

Closes #29725.

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packages/aws-cdk-lib/aws-elasticloadbalancingv2/lib/alb/application-target-group.ts

@@ -60,7 +60,7 @@ export interface ApplicationTargetGroupProps extends BaseTargetGroupProps {
    * After this period, the cookie is considered stale. The minimum value is
    * 1 second and the maximum value is 7 days (604800 seconds).
    *
-   * @default Duration.days(1)
+   * @default - Stickiness is disabled
    */
   readonly stickinessCookieDuration?: Duration;