add google_logging_metric to version 5 upgrade doc for #8780

[pengq-google]

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[modular-magician]

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[pengq-google]

@c2thorn This is the major release doc change for #8780
Thanks for your help along the way!

[modular-magician]

Hi there, I'm the Modular magician. I've detected the following information about your changes:

Diff report

Your PR generated some diffs in downstreams - here they are.

Terraform GA: Diff ( 1 file changed, 14 insertions(+))
Terraform Beta: Diff ( 1 file changed, 14 insertions(+))

[c2thorn]

I believe this has failed because there are now conflicts @pengq-google

[pengq-google]

replaced by #8886