chore(kms): incorrect parameter name in doc (#29234)

Closes #29222.

----

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

Author: msambol

packages/aws-cdk-lib/aws-kms/README.md

@@ -77,7 +77,7 @@ import * as cloudtrail from 'aws-cdk-lib/aws-cloudtrail';
 const myKeyAlias = kms.Alias.fromAliasName(this, 'myKey', 'alias/aws/s3');
 const trail = new cloudtrail.Trail(this, 'myCloudTrail', {
   sendToCloudWatchLogs: true,
-  kmsKey: myKeyAlias,
+  encryptionKey: myKeyAlias,
 });
 ```