Add https security to cloud-functions-v1 module

[mibelbahri]

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Checklist

I applicable, I acknowledge that I have:

• Read the contributing guide
• Ran terraform fmt on all modified files
• Regenerated the relevant README.md files using tools/tfdoc.py
• Made sure all relevant tests pass

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[wiktorn]

Looks good and thanks for fixing this outstanding bug in tfdoc.py!