Fix mapper_parsing_exception when parsing event_time

[r00tu53r]

What does this PR do?

The PR fixes the error with the way date processor is used. The date processor in the pipeline sets the @timestamp field from the given format but leaves the event_time field in its SQL server format which is not strict_date_optional_time||epoch_millis as expected by elasticsearch default date formats. The fix is to remove this field as the value has been stored in @timestamp.

Checklist

• I have reviewed tips for building integrations and this pull request is aligned with them.
• I have verified that all data streams collect metrics or logs.
• I have added an entry to my package's changelog.yml file.
• I have verified that Kibana version constraints are current according to guidelines.

How to test this PR locally

• Run pipeline tests elastic-package test pipeline
• Run system tests manually by setting up a windows agent with SQL Server on it.

[elasticmachine]

Pinging @elastic/security-external-integrations (Team:Security-External Integrations)

[P1llus]

LGTM!

[elasticmachine]

💚 Build Succeeded

the below badges are clickable and redirect to their specific view in the CI or DOCS
[](https://ci-stats.elastic.co/app/apm/services/beats-ci/transactions/view?rangeFrom=2022-03-10T09:18:09.339Z&rangeTo=2022-03-10T09:38:09.339Z&transactionName=BUILD Ingest-manager/integrations/PR-{number}&transactionType=job&latencyAggregationType=avg&traceId=e0fa31c1c6507da6aad959f8a6d5b7d0&transactionId=c346281a13e05da8)

Expand to view the summary

Build stats

• Start Time: 2022-03-10T09:28:09.339+0000

• Duration: 11 min 1 sec

Test stats 🧪

Test	Results
Failed	0
Passed	4
Skipped	0
Total	4

🤖 GitHub comments

To re-run your PR in the CI, just comment with:

• /test : Re-trigger the build.

[efd6]

Looks like you need to regenerate the test expectations.