Fix ApigeeEnvironment update response type.

[modular-magician]

This PR fixes the ApigeeEnvironment update response type according to the public documentation.

The issue is related to the fact that after requesting the update to ApigeeEnvironment here, the provider expects that the response will contain the Operation details to then wait for the Operation to complete here. Unlike Environment create request, which returns Operation, the update response has a type Environment according to the public docs, meaning that the ApigeeOperationWaitTime tries to process the Environment as Operation.

The Operation has a name key that is used to track its progress. However, the Environment also has a name key that contains the name of the Environment. That's why the users may see a weird apigee.googleapis.com/v1/<env-name>?alt=json GET requests that result in 404 Not Found while doing an update to their environments. In that case, the ApigeeOperationWaitTime interprets <env-name> as the operation name.

Here's a fix to a similar issue for the ApigeeOrganization: GoogleCloudPlatform/magic-modules#12413

Release Note Template for Downstream PRs (will be copied)

See Write release notes for guidance.

apigee: fixed error 404 for `environment` update requests.

Derived from GoogleCloudPlatform/magic-modules#12415