replace deprecated apache transport with recommended

[ckiosidis]

Fixes #<issue_number_goes_here> (it's a good idea to open an issue first for context and/or discussion)

Replaced the ApacheHttpTransport based on the recommendation at: https://github.com/googleapis/google-http-java-client/blob/master/google-http-client/src/main/java/com/google/api/client/http/apache/ApacheHttpTransport.java#L77-L78

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[elharo]

This is not as simple as it looks since it changes the public API surface.

[chingor13]

If we want to do something similar, we should create a v2 version and deprecate this existing one. See #1568