[BUG] SPARK_BUILTIN_FUNCTION_NAME_MAPPING doesn't work

[LantaoJin]

What is the bug?
https://github.com/opensearch-project/opensearch-spark/blob/0.5-nexus/ppl-spark-integration/src/main/java/org/opensearch/sql/ppl/utils/BuiltinFunctionTranslator.java

Above mapping should work but it doesn't

Query source = myglue_test.default.http_logs | eval c1 = is_not_null(request) | head 10
fail with

How can one reproduce the bug?
Steps to reproduce the behavior:

1. Go to '...'
2. Click on '....'
3. Scroll down to '....'
4. See error

What is the expected behavior?
A clear and concise description of what you expected to happen.

What is your host/environment?

• OS: [e.g. iOS]
• Version [e.g. 22]
• Plugins

Do you have any screenshots?
If applicable, add screenshots to help explain your problem.

Do you have any additional context?
Add any other context about the problem.

[LantaoJin]

No issue. close it.