[Fix][Core] Config variable substitution inconsistent

[xuqi1633]

Purpose of this pull request

#6840

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.

[liunaijie]

cool, can you also update the existing e2e test. change the sink from console to assert to verify the result are expected.

https://github.com/apache/seatunnel/blob/dev/seatunnel-e2e/seatunnel-engine-e2e/connector-seatunnel-e2e-base/src/test/java/org/apache/seatunnel/engine/e2e/UserVariableIT.java

https://github.com/apache/seatunnel/blob/dev/seatunnel-e2e/seatunnel-engine-e2e/connector-seatunnel-e2e-base/src/test/resources/fakesource_to_console.conf

[xuqi1633]

@liunaijie i have updated test variable

[liunaijie]

@liunaijie i have updated test variable

Please also update the config. add Assert sink to check the value are expected.

[liunaijie]

Assert config example: https://github.com/apache/seatunnel/blob/dev/seatunnel-e2e/seatunnel-connector-v2-e2e/connector-assert-e2e/src/test/resources/assertion/fake_full_types_to_assert.conf#L119

[xuqi1633]

@liunaijie is that so?

[liunaijie]

@xuqi1633 the test failed, please check.

[liunaijie]

the change not work, and please also update the other starter script.