Update # Google Cloud Integration readme

[ellis-elastic]

removed overview heading for consistency

Type of change

• Enhancement

What does this PR do?

removed overview heading for consistency

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

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: 2022-06-17T08:54:50.514+0000

• Duration: 17 min 54 sec

Test stats 🧪

Test	Results
Failed	0
Passed	24
Skipped	0
Total	24

🤖 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% (4/4)	💚
Files	100.0% (4/4)	💚 3.546
Classes	100.0% (4/4)	💚 3.546
Methods	98.246% (56/57)	👍 8.924
Lines	95.938% (1110/1157)	👍 5.08
Conditionals	100.0% (0/0)	💚

[elasticmachine]

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