Update generated code (#1663)

update generated code

src/CloudWatchLogsClient.php

@@ -40,6 +40,7 @@ class CloudWatchLogsClient extends AbstractApi
      * - Log group names can be between 1 and 512 characters long.
      * - Log group names consist of the following characters: a-z, A-Z, 0-9, '_' (underscore), '-' (hyphen), '/' (forward
      *   slash), '.' (period), and '#' (number sign)
+     * - Log group names can't start with the string `aws/`
      *
      * When you create a log group, by default the log events in the log group do not expire. To set a retention policy so
      * that events expire and are deleted after a specified time, use PutRetentionPolicy [^1].