trendmicro: handle presence of MSG-LEN in TCP messages

[efd6]

Proposed commit message

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

Related issues

• Relates trendmicro: add support for tls and test tcp/udp inputs #8563

Screenshots

[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: 2023-11-24T21:23:45.572+0000

• Duration: 17 min 3 sec

Test stats 🧪

Test	Results
Failed	0
Passed	9
Skipped	0
Total	9

🤖 GitHub comments

Expand to view the 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	22.222% (2/9)	👎 -77.778
Classes	22.222% (2/9)	👎 -77.778
Methods	33.333% (14/42)	👍
Lines	23.007% (101/439)	👎 -76.993
Conditionals	100.0% (0/0)	💚

[elasticmachine]

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

[kcreddy]

LGTM 👍🏼

[elasticmachine]

Package trendmicro - 1.8.1 containing this change is available at https://epr.elastic.co/search?package=trendmicro