feat(storage): Support bucket encryption config

[shubhangi-google]

This pull request significantly enhances the Google Cloud Storage client library by introducing comprehensive support for managing bucket encryption enforcement configurations. Users can now define and enforce default encryption behaviors for their buckets and files using customer-managed, customer-supplied, or Google-managed encryption keys. The changes provide robust API methods, update internal mechanisms for handling these configurations, and include practical examples and tests to ensure functionality and ease of use.

Highlights

• New Bucket Encryption Configuration Methods: Added new methods to Google::Cloud::Storage::Bucket for managing customer-managed, customer-supplied, and Google-managed encryption enforcement configurations, including getters and setters for customer_managed_encryption_enforcement_config, customer_supplied_encryption_enforcement_config, and google_managed_encryption_enforcement_config.
• Unified Encryption Update Method: Introduced a new update_bucket_encryption_enforcement_config method to handle updates for different types of bucket encryption enforcement configurations in a unified manner.
• Enhanced patch_gapi! Method: Modified the internal patch_gapi! method to accept an optional bucket_encryption_config parameter, allowing more flexible patching of encryption-related attributes.
• New Samples and Acceptance Tests: Included new samples and corresponding acceptance tests to demonstrate how to get, set, update, and remove bucket encryption enforcement configurations.
• Gemfile Updates: Added ostruct, cgi, and irb gems to the Gemfile for samples, addressing gems removed from Ruby core that are required for testing.

This Pr was created as old PR got corrupted - #32778, #32786

[snippet-bot]

Here is the summary of changes.

You are about to add 3 region tags.

• google-cloud-storage/samples/storage_get_bucket_encryption_enforcement_config.rb:15, tag storage_get_bucket_encryption_enforcement_config
• google-cloud-storage/samples/storage_set_bucket_encryption_enforcement_config.rb:15, tag storage_set_bucket_encryption_enforcement_config
• google-cloud-storage/samples/storage_update_bucket_encryption_enforcement_config.rb:17, tag storage_update_bucket_encryption_enforcement_config

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[bajajneha27]

Why are we doing this?

[shubhangi-google]

updated the mock expect method

[shubhangi-google]

Technical Update (for future reference ): Conditional "Effective Time" Behavior
In our latest testing of the encryption enforcement configs, we confirm that effectiveTime field is state-dependent:

When Enabling Restrictions (Not Restricted → Fully Restricted): The API returns an effectiveTime. This is the server’s way of confirming exactly when the new security policy became active.

When Disabling Restrictions (Fully Restricted → Not Restricted): The API omits the effectiveTime. Since the restriction has been removed, the field is no longer applicable and is stripped from the object hash.