Prior to this fix it worked only with `v1` APIs. `HttpJsonOperationsStub` is shared by multiple different services similarly to `GrpcOperationsStub`. Unlike grpc version, the verison of the actual API that this stub is used by is supposed to be encoded in the http url, so the `HttpJsonOperationsStub` must adjust to the actual version of the API it is being used from. Similarly we also need to make the url patterns less restrictive, to accept operaion names in different formats (this is what caused the `{name=}` pattern changes).

The solution is hacky, but simple and should work for all known APIs. It is based on the fact that even though the `HttpJsonOperationsStub` is shared by all clients (i.e. is in `gax`), its `HttpJsonStubCallbackFactory` argument, on the other hand, is a generated one (i.e. is in a gapic client for a specific API) and its package corresponds to the API version, which is a convention for all google APIs (i.e. version in the proto package corresponds to the version of the API).

Doing this the other way would require a lot of work (parsing yaml, generating operations stub on the fly etc), and we may come back to it if even needed (most probably never).

🤖 I have created a release *beep* *boop*
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### Updating meta-information for bleeding-edge SNAPSHOT release.

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