Support healthcare fhir new notifications config

[modular-magician]

Link: https://cloud.google.com/healthcare-api/docs/how-tos/pubsub#fhir_notifications_containing_fhir_resource_data
Fix: #12061

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Release Note Template for Downstream PRs (will be copied)

healthcare: added `notification_configs ` field to `google_healthcare_fhir_store` resource

Derived from GoogleCloudPlatform/magic-modules#6471

[github-actions]

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