[BUG] @timestamp field is not displayed when creating a report from a search

[Kruzerson]

Describe the bug

Hello. When I try to create a report from a search, the "@timestamp" field is not displayed in the report. How can I add it there?

To Reproduce
Steps to reproduce the behavior:

1. Go to 'Discover'
2. Click on 'Reporting'
3. Create report
4. No Timestamp

Expected behavior
I want to see a timestamp in report

OpenSearch Version
v 2.15.0

Dashboards Version
v 2.15.0

Screenshots

[huyaboo]

@opensearch-project/admin Please redirect to reporting dashboards

[dblock]

[Catch All Triage - 1, 2, 3, 4, 5]