[Fix][FakeSource] fix random from template not include the latest value issue

[liunaijie]

Purpose of this pull request

fix the FakeSource template random won't take the latest value issue.

Now using RandomUtils.nextInt(0, list.size() -1) to get the random index, but the Random.nextInt(start, end) the end is not included. so the latest value never will take.
update the Random.nextInt(0, list.size())

Does this PR introduce any user-facing change?

How was this patch tested?

Check list

• If any new Jar binary package adding in your PR, please add License Notice according
  New License Guide
• If necessary, please update the documentation to describe the new feature. https://github.com/apache/seatunnel/tree/dev/docs
• If you are contributing the connector code, please check that the following files are updated:
  1. Update change log that in connector document. For more details you can refer to connector-v2
  2. Update plugin-mapping.properties and add new connector information in it
  3. Update the pom file of seatunnel-dist
• Update the release-note.