Move filestore enterprise features out of beta and add support for cu…

[modular-magician]

Move Filestore enterprise features out of beta and add support for cmek for filestore instances

fixes hashicorp/terraform-provider-google#11173

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• [X ] Searched through the issue tracker for an open issue that this either resolves or contributes to, commented on it to claim it, and written "fixes {url}" or "part of {url}" in this PR description. If there were no relevant open issues, I opened one and commented that I would like to work on it (not necessary for very small changes).
• Generated Terraform, and ran make test and make lint to ensure it passes unit and linter tests.
• [X ] Ensured that all new fields I added that can be set by a user appear in at least one example (for generated resources) or third_party test (for handwritten resources or update tests).
• [X ] Ran relevant acceptance tests (If the acceptance tests do not yet pass or you are unable to run them, please let your reviewer know).
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Release Note Template for Downstream PRs (will be copied)

filestore: promoted enterprise features to GA
filestore: added `kms_key_name` field to `google_filestore_instance` resource to support CMEK

Derived from GoogleCloudPlatform/magic-modules#5875