google: Can't capture request and response when using streamEvents()

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Issue Content

This came up while I was looking to test #11602 and earlier related PRs. For most integration tests, we are able to see the JSON request and response, request headers, and other information useful for debugging issues. This was not available when testing streamEvents().

In the integration tests, the newChatGoogle() method that all the tests use creates a GoogleRequestRecorder and sets it as a callback. However the methods underlying streamEvents() are neither sending these callbacks, nor generating a new-style event to record the JSON, making debugging more difficult.