[Backport 2.x] Fix flat_object long field error

[opensearch-trigger-bot]

Backport 9e62ccf from #13259.

[github-actions]

❌ Gradle check result for 7da2ae5: FAILURE

Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green. Is the failure a flaky test unrelated to your change?

[dblock]

❌ Gradle check result for 7da2ae5: FAILURE

Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green. Is the failure a flaky test unrelated to your change?

org.opensearch.search.profile.query.QueryProfilerTests.testBasic {p0=5}

#10941

[github-actions]

❌ Gradle check result for 7da2ae5: FAILURE

Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green. Is the failure a flaky test unrelated to your change?

[github-actions]

❌ Gradle check result for 7da2ae5: FAILURE

Please examine the workflow log, locate, and copy-paste the failure(s) below, then iterate to green. Is the failure a flaky test unrelated to your change?

[dblock]

Failing on :distribution:bwc:maintenance:buildBwcLinuxTar, needs a rebase?

[github-actions]

✅ Gradle check result for 3762e32: SUCCESS

[dblock]

I am puzzled why :server:japicmp is failing here, and it's failing locally for me too, but not in all the other backport PRs. I had already tried to rebase this one without any change.

Opened #13385.

[github-actions]

✅ Gradle check result for b5fe8be: SUCCESS