Update provider-defined function documentation examples

[SarahFrench]

This PR updates documentation for some provider-defined functions to include richer examples of their usage.

Release Note Template for Downstream PRs (will be copied)

[SarahFrench]

/gcbrun

[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.

google provider: Diff ( 3 files changed, 144 insertions(+), 14 deletions(-))
google-beta provider: Diff ( 3 files changed, 144 insertions(+), 14 deletions(-))