Camera: batching dequeueBuffer call for batched requests

Add plumbing to call into batched version of getBuffer call.
Also add some logic so batched version can be used even
when camera HAL is request buffer one at a time.

Camera3OutputStream will batch dequeue buffers on a batch unit.
This way we can save extra IPCs even when the client (camera
framework or camera HAL) does not call into batch dequeue API
(dequeueBuffers) directly.

As a safety measure, right before client is about to return
all outstanding buffers, all prefetched buffers will also
be returned.

TODO:
  - Consider also batch queueBuffer path
  - switch to batch API in requestStreamBuffer API

Test: GCA high speed recording
Bug: 113788435
Change-Id: I3cc0b62e8a6891d6ff6cad0e3c78e1d7abff6317