BQ: add setMaxDequeuedBufferCount

Adds the new setMaxDequeuedBufferCount() function to
BufferQueueProducer. This will eventually replace setBufferCount.

Also add setAsyncMode.

Bug 13174928

Change-Id: Iea1adcd5d74a75f67d8e9dde06d521695628ad5a
14 files changed