fireeye: fix invalid value in sample event

[efd6]

What does this PR do?

This fixes the invalid event.type value in the sample event that was missed in #3099.

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.

Author's Checklist

• [ ]

How to test this PR locally

See #3016 (comment)

Related issues

• Closes fireeye using invalid field values according to ECS #3053

Screenshots

[elasticmachine]

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

[elasticmachine]

💚 Build Succeeded

the below badges are clickable and redirect to their specific view in the CI or DOCS

Expand to view the summary

Build stats

• Start Time: 2022-05-12T06:42:09.055+0000

• Duration: 17 min 30 sec

Test stats 🧪

Test	Results
Failed	0
Passed	7
Skipped	0
Total	7

🤖 GitHub comments

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

• /test : Re-trigger the build.

[elasticmachine]

🌐 Coverage report

Name	Metrics % (covered/total)	Diff
Packages	100.0% (1/1)	💚
Files	100.0% (2/2)	💚 3.597
Classes	100.0% (2/2)	💚 3.597
Methods	100.0% (18/18)	💚 11.753
Lines	82.462% (489/593)	👎 -6.651
Conditionals	100.0% (0/0)	💚