Don't recreate GCE instances when updating resource_policies property

[modular-magician]

This fixes the behaviour described in #9981.
Basically, the change removes the ForceNew attribute from the resource_policies property of google_compute_instance and adds code to check for changes of the property. If the property changed, all old values get removed and all new values (if there are any) get added.
The change was previously submitted in #10029

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Release Note Template for Downstream PRs (will be copied)

compute: Fixed recreation of GCE instances when updating `resource_policies` property

Regarding tests: There doesn't seem to be a test specific for this behaviour. Do you need me to create one?

Derived from GoogleCloudPlatform/magic-modules#5206

[github-actions]

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