Harden BufferHubQueueProducerTest

This is a test that covers our implementation of bufferhubqueue-based
IGraphicBufferProducer, which eventually enables VrCore/VrFlinger to
access buffers produced from other Android compontents. Note that the
gtest itself is a (slightly) modified version of
IGraphicBufferProducer_test.cpp.

This also improves BufferHubQueue in the following way to support more
features of android::BufferQueue.
1/ Supports more buffer queue parameters that we query.
2/ BufferHubQueue (the PDX client) now supports default width, height,
and format configuration.
3/ Change default max_dequeue_buffer_count to 1 (which is the same
behavior current android::BufferQueue adopts).
4/ Fill in |QueueBufferOutput| during |enqueueBuffer|.

Bug: 34197998
Bug: 36266201
Test: build and run buffer_hub_queue_producer-test
Change-Id: I9d3e8bb66dbfb66e67ab7b0e5093e49a3f374e9c