Added missing meta.yaml fields for instance_template and igm

[melinath]

Ran a script to identify missing fields in meta.yaml and added them by hand after confirming mappings.

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[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, 37 insertions(+))
google-beta provider: Diff ( 4 files changed, 55 insertions(+))