update version_5_upgrade.html.markdown for provider Zone and Region V…

[BBBmau]

…alues

References this PR #8587

If this PR is for Terraform, I acknowledge that I have:

• Searched through the issue tracker for an open issue that this either resolves or contributes to, commented on it to claim it, and written "fixes {url}" or "part of {url}" in this PR description. If there were no relevant open issues, I opened one and commented that I would like to work on it (not necessary for very small changes).
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• Generated Terraform providers, and ran make test and make lint in the generated providers to ensure it passes unit and linter tests.
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• Read Write release notes before writing my release note below.

Release Note Template for Downstream PRs (will be copied)

[modular-magician]

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[SarahFrench]

l left a few bits of feedback around the theme of writing this guide with users as our intended audience. Overall, I think writing this addition to the guide is tough as someone new to the Google provider, so thank you for preparing this draft! 😁

Next week we can get some more eyes on this PR from the Google team to help figure out how much detail to include.

[SarahFrench]

Superseded by #9008

(I've put us as co-committers there!)