Fix the length of the valueHelp on the --sample option for the create command, and turn on wrapping. (#28264)

The wrapping for some commands was never actually turned on, so this turns it on.

Also, it shortens the `valueHelp` for the `--sample` option to be just "id" instead of "the sample ID of the desired sample from the API documentation website (http://docs.flutter.io)", which was causing the line to get far too long.

Fixes #23074