[BUG] Unit test OpenSearchClientUtilsSuite fails locally

[dai-chen]

What is the bug?

OpenSearchClientUtilsSuite test fails locally.

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

$ sbt test

[info] OpenSearchClientUtilsSuite:
[info] sanitizeIndexName
[info] - should percent-encode invalid OpenSearch index name characters and lowercase all characters *** FAILED ***
[info]   null was not equal to "test%20%3a%22%2b%2f%5c%7c%3f%23%3e%3c" (OpenSearchClientUtilsSuite.scala:16)

What is the expected behavior?

The test is expected to pass locally to unblock local test.

Do you have any additional context?

N/A